Federal Executive Branch
Here's a look at documents from the U.S. Executive Branch
Featured Stories
SBA Highlights Working Capital Loans for U.S. Homebuilders
WASHINGTON, March 4 -- The Small Business Administration issued the following news release:
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SBA Highlights Working Capital Loans for U.S. Homebuilders
Up to $5 Million in Flexible Financing Available for Local Builders as Mortgage Rates Hit 3-Year Low for Homebuyers
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With U.S. mortgage rates dropping to below 6% for the first time in three years, the U.S. Small Business Administration (SBA) is highlighting for homebuilders the 7(a) Working Capital Pilot (WCP) Program. With access to capital, homebuilders can accelerate residential construction and increase housing availability for American
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WASHINGTON, March 4 -- The Small Business Administration issued the following news release:
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SBA Highlights Working Capital Loans for U.S. Homebuilders
Up to $5 Million in Flexible Financing Available for Local Builders as Mortgage Rates Hit 3-Year Low for Homebuyers
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With U.S. mortgage rates dropping to below 6% for the first time in three years, the U.S. Small Business Administration (SBA) is highlighting for homebuilders the 7(a) Working Capital Pilot (WCP) Program. With access to capital, homebuilders can accelerate residential construction and increase housing availability for Americanfamilies with expanded access to capital. As the country recovers from Biden-era inflation, onerous housing regulations, supply-chain disruptions, and the resulting new home shortages, the Trump SBA offers builders project-based lines of credit up to $5 million, and up to 100% financing of direct project costs, including labor, materials, and subcontractors.
"Since Day One, the Trump Administration has taken decisive action to make homeownership affordable again, and to back the local builders who help make the dream of buying a home possible," said SBA Administrator Kelly Loeffler. "Through the 7(a) Working Capital Pilot Program, the SBA offers builders access to up to $5 million in flexible project financing - enabling them to break ground sooner, build efficiently, and deliver new homes for hardworking families. Through local lenders, we're offering homebuilders the capital needed to meet the demand for housing amid improving affordability and rising housing starts."
The WCP features a flexible SBA guarantee fee designed to accommodate each borrower's unique financing needs. The guarantee fee is set at 0.25% for the first 12 months, and 0.275% for each additional 12-month period, with loan terms available for up to 60 months based on borrower and project requirements. This annualized cost framework enables homebuilders to maintain a ready line of credit that can be efficiently deployed as new projects start.
When used by general contractors, the WCP can provide the dedicated working capital necessary to compete for and perform larger contracts. Homebuilders can leverage the program to finance project costs in residential housing developments, including those located in Opportunity Zones - empowering local builders to contribute to growing the nation's housing supply. WCP loans may be structured as a revolving or non-revolving project-based line of credit, support both single- and multi-phase contracts, and are tailored to meet the needs of each homebuilder.
President Trump has taken a whole-of-government approach to make homeownership affordable again, including cutting inflation, wasteful government spending, supply chain dependence, and burdensome regulations - all of which drove up housing costs and impacted housing supply. As a result, mortgage rates have now fallen to their lowest level since 2022, underscoring the Administration's ongoing commitment to lowering costs. The National Association of Realtors' Housing Affordability Index has climbed to its highest level since March 2022 as family incomes rise and rates moderate, marking seven straight months of improvement. Builders are accelerating construction, with housing starts at a five-month high.
Builders interested in learning more about the 7(a) Working Capital Pilot Program can email 7aWCP@sba.gov to connect with an SBA working capital specialist.
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About the U.S. Small Business Administration
The U.S. Small Business Administration helps power the American dream of entrepreneurship. As the leading voice for small businesses within the federal government, the SBA empowers job creators with the resources and support they need to start, grow, and expand their businesses or recover from a declared disaster. It delivers services through an extensive network of SBA field offices and partnerships with public and private organizations. To learn more, visit www.sba.gov.
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Original text here: https://www.sba.gov/article/2026/03/03/sba-highlights-working-capital-loans-us-homebuilders
Office of Advocacy: Labor Department's 2024 Independent Contractor Rule on Chopping Block
WASHINGTON, March 4 -- The Small Business Administration's Office of Advocacy issued the following news release:
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Labor Department's 2024 Independent Contractor Rule on Chopping Block
The Office of Advocacy, the independent voice for small business within the executive branch, applauds the U.S. Department of Labor (DOL) for proposing a rule to rescind the Biden-era independent contractor regulation, paving the path for flexibility in hiring freelancers and gig workers. If enacted, the Labor Department's proposed rule is estimated to save U.S. small businesses $2.31 billion over the coming
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WASHINGTON, March 4 -- The Small Business Administration's Office of Advocacy issued the following news release:
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Labor Department's 2024 Independent Contractor Rule on Chopping Block
The Office of Advocacy, the independent voice for small business within the executive branch, applauds the U.S. Department of Labor (DOL) for proposing a rule to rescind the Biden-era independent contractor regulation, paving the path for flexibility in hiring freelancers and gig workers. If enacted, the Labor Department's proposed rule is estimated to save U.S. small businesses $2.31 billion over the coming10-year period (discounting at 7%), amounting to $329 million in annualized cost savings.
The 2024 DOL independent contractor rule used a six-factor test that frequently categorized independent contractors as employees, paving the way for more paperwork and expenses in addition to higher legal risks.
DOL's proposed rule instead concentrates on economic dependence and specifically on two fundamental factors:
1. Control over work: Does the worker decide how, when, and for whom they work?
2. Chance to make profits: Can the worker earn extra money or lose money depending on how they manage their work, make business choices, or spend their own money?
If the two factors suggest that the worker is either an employee or an independent contractor, there is a substantial likelihood that it is the accurate classification for the worker. Additionally, the DOL's proposed rule considers skill, how long the work lasts, and whether the work is part of a bigger production team.
"Small businesses throughout the U.S. have shared with Advocacy that the Biden Administration's independent contractor rule has amounted to uncertainty, more paperwork, more expenses, and more headaches," said Dr. Casey B. Mulligan, Chief Counsel of Advocacy. "It is refreshing to see federal agencies listen to and take into account the voices of our nation's small businesses."
Advocacy created the "Most Wanted" reforms list as a result of hearing directly from thousands of small businesses about the regulatory burdens they face. The 2024 independent contractor rule is one of nine rules on Advocacy's "Most Wanted" reforms identified for rescission, withdrawal, or modification to lessen small businesses' regulatory burden. If implemented, the associated deregulatory actions could save small businesses over $150 billion in compliance costs. Learn more about the "Most Wanted" reforms list.
To submit a public comment on the Labor Department's proposed rule, visit federalregister.gov.
During the first year of the Trump 47 Administration, Advocacy worked with federal agencies to save small businesses $110 billion in regulatory costs. The office met with more than 12,000 small businesses in 48 states and launched the Red Tape Hotline to gather feedback from U.S. small businesses about regulatory burdens and share it with the White House, Congress, and federal agencies with the goal of slashing red tape. Learn more about Advocacy's other highlights in the First Year Report.
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Created by Congress in 1976, the Office of Advocacy of the U.S. Small Business Administration is an independent voice for small business within the executive branch. Appointed by the President and confirmed by the U.S. Senate, the Chief Counsel for Advocacy directs the office. The Chief Counsel advances the views, concerns, and interests of small business before Congress, the White House, federal agencies, federal courts, and state policymakers. Economic research, policy analyses, and small business outreach help identify issues of concern. Regional Advocates and an office in Washington, DC, support the Chief Counsel's efforts. For more information on the Office of Advocacy, visit advocacy.sba.gov or call (202) 205-6533.
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Original text here: https://advocacy.sba.gov/2026/03/03/labor-departments-2024-independent-contractor-rule-on-chopping-block/
OCC Issues Final Rules to Reduce Regulatory Burden for Community Banks
WASHINGTON, March 4 -- The U.S. Department of the Treasury Office of the Comptroller of the Currency issued the following news release on March 3, 2026:
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OCC Issues Final Rules to Reduce Regulatory Burden for Community Banks
The Office of the Comptroller of the Currency (OCC) today announced two final rules to reduce the regulatory burden for community banks.
These actions build upon the OCC's ongoing efforts to tailor bank supervision and regulation to bank risk profile and reduce burden for its regulated institutions so they can focus resources on core functions and support economic
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WASHINGTON, March 4 -- The U.S. Department of the Treasury Office of the Comptroller of the Currency issued the following news release on March 3, 2026:
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OCC Issues Final Rules to Reduce Regulatory Burden for Community Banks
The Office of the Comptroller of the Currency (OCC) today announced two final rules to reduce the regulatory burden for community banks.
These actions build upon the OCC's ongoing efforts to tailor bank supervision and regulation to bank risk profile and reduce burden for its regulated institutions so they can focus resources on core functions and support economicgrowth.
"Community banks serve critical constituencies and lend to Main Street businesses, that in turn support vibrant local economies," said Comptroller of the Currency Jonathan V. Gould. "Unfortunately, over the last couple of decades, regulatory burdens coupled with the proliferation of a one-size-fits-all supervisory framework have cut the number of community banks across our nation in half. As Comptroller, I've prioritized addressing the challenges of community banks by streamlining regulation and tailoring supervision. Today's actions execute on meaningful reforms as we continue working to help these institutions best serve the American people on a level playing field."
In a final rule, the OCC rescinded its Fair Housing Home Loan Data System regulation, removing obsolete and largely duplicative data collection requirements on applications for home loans that applied only to national banks. The final rule eliminates regulatory burden for these institutions without having a material impact on the availability of data necessary for the OCC to conduct its fair housing-related supervisory activities.
In a separate final rule, the OCC simplified licensing requirements for corporate activities and transactions involving community banks. The final rule broadens eligibility for expedited or reduced filing procedures to community banks. These changes are intended to reduce burden related to corporate activities and transactions by community banks.
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Original text here: https://occ.gov/news-issuances/news-releases/2026/nr-occ-2026-13.html
NOAA: West Coast Waters Experiencing Another Large Marine Heatwave
WASHINGTON, March 4 -- The U.S. Department of Commerce National Oceanic and Atmospheric Administration issued the following news:
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West Coast Waters Experiencing Another Large Marine Heatwave
NOAA scientists track growth of heatwaves that can affect fisheries.
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A massive marine heatwave has dominated waters off the West Coast since last summer. This marks only the third time on record that such a large section of the coastal ocean has remained so warm for so long--particularly into winter months--without it being an El Nino, NOAA scientists report. NOAA Fisheries and our partners are
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WASHINGTON, March 4 -- The U.S. Department of Commerce National Oceanic and Atmospheric Administration issued the following news:
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West Coast Waters Experiencing Another Large Marine Heatwave
NOAA scientists track growth of heatwaves that can affect fisheries.
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A massive marine heatwave has dominated waters off the West Coast since last summer. This marks only the third time on record that such a large section of the coastal ocean has remained so warm for so long--particularly into winter months--without it being an El Nino, NOAA scientists report. NOAA Fisheries and our partners aretracking possible heatwave impacts, which can include harmful algal blooms that can sicken marine mammals and close shellfish fisheries.
Third Time As Warm
At one point last September, the current marine heatwave rivaled the enormous 2013-2016 marine heatwave known as "The Blob" in terms of size and surface temperatures. The current heatwave has raised the temperature of waters along the West Coast roughly 3 to 4 degrees Fahrenheit above normal. On September 9, 2025, the northeast Pacific reached its highest ever average temperature of 20.6 degrees Celsius, or about 69 degrees Fahrenheit. That's almost a half-degree warmer than ever before. Past marine heatwaves shook up marine ecosystems that drove shifts of species, die-offs, and other disruptions of ecosystems in the Northeast Pacific Ocean.
"We have forecast tools that provide some insight, but we are also watching carefully for implications on the marine ecosystem," said Andrew Leising, a research oceanographer at NOAA Fisheries' Southwest Fisheries Science Center. He runs the California Current Marine Heatwave Tracker . The tracker has been documenting marine heatwaves off the West Coast through NOAA data from satellites, ships, and buoys since 2019.
The North Pacific has repeatedly hit record or near-record temperatures since The Blob. Like others before it, the current marine heatwave weakened and receded from the coast in October and November 2025. Unlike others, it has since strengthened and returned. "We're in La Nina, but water temperatures along our coast look much different," Leising said. "The conditions are hard to reconcile. We want to be cautious in our interpretation, but at the same time this is not a situation that we have seen before."
Heatwaves Shift Species
The current heatwave has brought news of species in unusual areas, such as tunas caught in large numbers in Alaska last fall. The Blob and other marine heatwaves have been shown to reduce the survival of salmon in the ocean, leaving fewer fish to catch and to return to rivers to spawn. "We know these marine heatwaves alter ecosystem conditions, which affects fish and other marine life," Leising said. "We're very interested in what the fishing fleet and others who are out on the water are seeing and are looking into new ways to collect this information. Are there species in unusual places, or what might be changing?"
In addition, the unusual warmth could begin to set the stage for a repeat of last year's harmful algal bloom off Southern California. It hit unusually early in 2025 and killed hundreds of California sea lions, dolphins, and seabirds. Harmful algal blooms can also close fisheries, especially recreational fisheries involving shellfish that concentrate the toxins, affecting the coastal economy.
Looking Ahead in 2026
"Although rivaling the Blob in area, the current marine heatwave has had much less ecological impact since so far since it has not penetrated as deeply into the water column, and has not spent as much time near the coast," said Leising.
NOAA's marine heatwave forecasts suggest that the warm waters may dissipate in the coming months as warm surface waters mix with cooler water from below, said Michael Jacox, a research scientist at the Southwest Fisheries Science Center. If that happens, however, one key question is whether enough warmer waters will remain to combine with the nutrients to fuel another bloom of harmful algae.
"We are in uncharted conditions, so we need to assess the most likely outcome given what we know," Leising said. "This is what makes the ocean so interesting. We see different pieces of the picture, but ultimately it's the marine ecosystem that brings those together and demonstrates where the conditions are leading us."
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Original text here: https://www.fisheries.noaa.gov/feature-story/west-coast-waters-experiencing-another-large-marine-heatwave
Federal Jury Finds Former San Diego County Sheriff's Deputy Guilty in Fatal Shooting of Unarmed Fleeing Arrestee
SAN DIEGO, California, March 4 -- The office of the U.S. Attorney for the Southern District of California posted the following news release on March 3, 2026:
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Federal Jury Finds Former San Diego County Sheriff's Deputy Guilty in Fatal Shooting of Unarmed Fleeing Arrestee
A federal jury today convicted former San Diego County Sheriff's Deputy Aaron Richard Russell in the fatal shooting of a 36-year-old unarmed man who was shot four times from behind while running away from authorities.
Following a two-week trial and less than seven hours of deliberation, the jury found that Russell violated
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SAN DIEGO, California, March 4 -- The office of the U.S. Attorney for the Southern District of California posted the following news release on March 3, 2026:
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Federal Jury Finds Former San Diego County Sheriff's Deputy Guilty in Fatal Shooting of Unarmed Fleeing Arrestee
A federal jury today convicted former San Diego County Sheriff's Deputy Aaron Richard Russell in the fatal shooting of a 36-year-old unarmed man who was shot four times from behind while running away from authorities.
Following a two-week trial and less than seven hours of deliberation, the jury found that Russell violatedthe civil rights of the victim in taking his life by shooting him in the back as he ran away. He was convicted on both counts filed against him - Deprivation of Rights Under Color of Law and Use and Discharge of a Firearm During and In Relation to a Crime of Violence.
Russell is scheduled to be sentenced on May 29, 2026, before U.S. District Judge Todd W. Robinson. He was allowed to remain free on bond. Russell faces a 10-year mandatory minimum sentence and up to life in prison.
"This is an important verdict because it demonstrates our commitment to impartially and unceasingly seeking justice," said U.S. Attorney Adam Gordon.
"Civil rights have long been a priority for the FBI," said Acting Special Agent in Charge TJ Holland of the FBI San Diego Field Office. "In conjunction with the U.S. Attorney's Office, the FBI will vigorously investigate any potential violations."
According to evidence presented at trial, on May 1, 2020, Russell - who at the time was a deputy with the San Diego Sheriff's Department - fired five shots at the victim, N.B. - who was unarmed - as he attempted to flee from custody while California State Parks Police officers were transporting him to the San Diego Central Jail in downtown San Diego. The victim was struck multiple times, including once squarely in the back. That shot punctured his lung and struck his heart, and N.B. died as a result of the multiple gunshots.
The initial encounter with the victim began on the afternoon of May 1, 2020, when a California State Parks officer approached N.B. in the Old Town State Historic Park because she saw him hitting golf balls to his dog while the park was closed by COVID-19 regulations. N.B. ran from the officer, who chased him on foot.
A short time later, N.B. was taken into custody. He was searched and handcuffed before being placed into the back of a law enforcement vehicle for transport to the San Diego Central Jail, located at Front and B Streets in downtown San Diego. Due to COVID-19 protocols in place at the time, the officers traveled in separate vehicles.
The transport was uneventful until they arrived at the intersection in front of the jail. As they pulled through the intersection and up to the jail's sallyport, N.B. slipped one hand free from his handcuffs, managed to get his arm through the partially lowered rear passenger window - which had been lowered pursuant to a COVID-19 protocol to allow for ventilation - and was able to open the rear passenger door from the outside.
N.B. opened the rear door, exited the sedan, and briefly attempted to prevent the California State Parks officer in the other vehicle from exiting his truck before turning and running northbound on Front Street. That officer was only momentarily delayed and chased N.B., only a few feet behind.
At the same time, the defendant and another deputy were standing at the intersection of Front and B Streets. The defendant immediately stepped into the street, drew his firearm, and fired five shots in rapid succession at close range. No other officer even pulled their firearm, and at trial, multiple officers testified that it was apparent that N.B. was not a threat to anyone, that they never for a moment considered shooting N.B., and that it "wasn't even a close call." Other eyewitnesses, including a nurse and a firefighter, testified that they were "shocked" that the defendant shot N.B. in the back.
Four of the rounds fired by the defendant struck N.B., including one that entered his back and fatally pierced his heart and lung. N.B. staggered to the northwest corner of Front and B Streets, where he collapsed, his body falling half on the sidewalk and half in a planter next to a tree. Other officers and paramedics tried to save his life, but he was pronounced dead shortly after being transported to the hospital.
The shooting was captured on multiple surveillance cameras along Front Street, as well as on body-worn camera footage from officers who responded to the scene shortly afterward. The fifth round fired by the defendant struck the driver's side fog lamp of a civilian's vehicle that was traveling southbound on Front Street.
The defendant was indicted by a federal grand jury on May 16, 2024. Russell's first trial on the charged offenses in May 2025 ended when the jury could not reach a unanimous verdict.
This case is being prosecuted by Assistant U.S. Attorneys Seth Askins and Michael Songer and Department of Justice Civil Rights Trial Attorney Lia Wright Tesconi.
DEFENDANT ... Case Number 24-cr-1015-TWR
Aaron Richard Russell ... Age: 29
SUMMARY OF CHARGES
Deprivation of Rights Under Color of Law Using a Dangerous Weapon and Resulting in Death - 18 U.S.C. Sec. 242
Maximum penalty: Life in prison and $500,000 fine
Use and Discharge of a Firearm During and In Relation to a Crime of Violence - 18 U.S.C. Sec. 924(c)
Maximum penalty: Mandatory Minimum 10 years in prison and $500,000 fine
INVESTIGATING AGENCY
Federal Bureau of Investigation
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Original text here: https://www.justice.gov/usao-sdca/pr/federal-jury-finds-former-san-diego-county-sheriffs-deputy-guilty-fatal-shooting
FMCSA Seeks 18 Drivers to Help Test HOS Pilot Programs
WASHINGTON, March 4 -- The U.S. Department of Transportation Federal Motor Carrier Safety Administration issued the following news release:
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FMCSA Seeks 18 Drivers to Help Test HOS Pilot Programs
FMCSA currently seeks 18 drivers to help the agency test and fine-tune two upcoming hours-of-service pilot programs. Over the course of six weeks, these drivers will help us make sure the study plans, training materials, and data collection tools are clear, practical, and ready for broader rollout.
This short, pre-testing phase is an important step in developing the Flexible Sleeper Berth and
... Show Full Article
WASHINGTON, March 4 -- The U.S. Department of Transportation Federal Motor Carrier Safety Administration issued the following news release:
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FMCSA Seeks 18 Drivers to Help Test HOS Pilot Programs
FMCSA currently seeks 18 drivers to help the agency test and fine-tune two upcoming hours-of-service pilot programs. Over the course of six weeks, these drivers will help us make sure the study plans, training materials, and data collection tools are clear, practical, and ready for broader rollout.
This short, pre-testing phase is an important step in developing the Flexible Sleeper Berth andSplit Duty Period pilot programs. Both efforts are part of the U.S. Department of Transportation Secretary Sean P. Duffy's Pro-Trucker Package and support President Donald Trump's Executive Order 14286, Enforcing Commonsense Rules of the Road for America's Truck Drivers.
The goal of these programs is to test alternatives to the current hours-of-service requirements which have the potential to improve the lives and working conditions of American truck drivers through greater flexibility, while simultaneously maintaining equal or greater levels of safety.
FMCSA is working with researchers at Virginia Tech Transportation Institute (VTTI) to develop and carry out these hours-of-service pilot programs. To vet the research designs and identify any issues with data collection tools, FMCSA needs drivers to sign up for the six-week pre-tests with VTTI.
The Agency is seeking nine drivers who currently use "split sleeper berth" options (either "8/2" or "7/3") and, most importantly, who want to test regularly using one or both of these new split options ("6/4" and "5/5") for six weeks.
FMCSA also needs nine drivers whose schedules currently and regularly require them to drive up to the end of their 14-hour "driving window" and would also like to test the option to "pause" the window for 30 minutes minimum and up to 3 hours maximum by taking an extra break either:
(a) off-duty or in the sleeper berth in any location, or,
(b) on-duty (not driving) at the location of a pickup or delivery of cargo
If you are a driver and would like to apply to participate in the limited pre-testing, visit FMCSA's Hours-of-Service webpage or follow the links below.
Flexible Sleeper Berth Online Screening Questionnaire
Split Duty Period Online Screening Questionnaire
Please share this information across your networks.
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Original text here: https://www.fmcsa.dot.gov/newsroom/fmcsa-seeks-18-drivers-help-test-hos-pilot-programs
DOE Lawrence Berkeley National Laboratory: Electron Microscopy Technique Reveals Atomic Structures From Nanocrystals Once Considered Unsolvable
WASHINGTON, March 4 (TNSjou) -- The U.S. Department of Energy Lawrence Berkeley National Laboratory issued the following news:
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New Electron Microscopy Technique Reveals Atomic Structures From Nanocrystals Once Considered Unsolvable
'Virtual apertures' let researchers isolate and solve atomic structures from individual nanocrystals embedded in dense clusters, providing valuable new data for energy and pharmaceutical applications.
Key Takeaways
* Berkeley Lab scientists developed a new way to determine atomic structures from nanocrystals previously considered unusable for crystallography.
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... Show Full Article
WASHINGTON, March 4 (TNSjou) -- The U.S. Department of Energy Lawrence Berkeley National Laboratory issued the following news:
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New Electron Microscopy Technique Reveals Atomic Structures From Nanocrystals Once Considered Unsolvable
'Virtual apertures' let researchers isolate and solve atomic structures from individual nanocrystals embedded in dense clusters, providing valuable new data for energy and pharmaceutical applications.
Key Takeaways
* Berkeley Lab scientists developed a new way to determine atomic structures from nanocrystals previously considered unusable for crystallography.
*By combining 4D-STEM with computational "virtual apertures," the team can isolate and analyze individual nanocrystals embedded within dense clusters -- without requiring large, pristine samples.
* The results represent the first single-crystal structures determined from 4D-STEM data by direct methods at subangstrom resolution.
By Theresa Duque
Scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a new way to determine atomic structures from nanocrystals previously considered unusable, a breakthrough that could transform how researchers study materials too small or imperfect for conventional crystallography.
Crystalline materials have enabled advances in computing, communications, energy technologies, and pharmaceuticals. Many of these materials' unique properties arise from the way in which their constituent molecules form repeating patterns. To better understand how to develop crystalline materials into useful technologies, scientists need to determine their atomic structure. Unfortunately, their samples don't always cooperate. Although established techniques like X-ray crystallography can deliver beautiful maps of atomic structure at subangstrom resolution, they require large, pristine single crystals to work, and many important materials refuse to grow that way.
Now, in a recent study published in the Proceedings of the National Academy of Sciences (PNAS) (https://www.pnas.org/doi/10.1073/pnas.2508185122), Berkeley Lab scientists have developed an approach that can sample single nanocrystals embedded within agglomerated clusters, transforming once-problematic materials into valuable sources of data.
"Our technique allows us to selectively mine data from the best areas of a nanoscale sample, which is a game changer for crystallography," said senior author Peter Ercius, staff scientist at the Molecular Foundry's National Center for Electron Microscopy (NCEM) facility.
Using a technique called 4D-STEM (four-dimensional scanning transmission electron microscopy), the Berkeley Lab researchers shrink the electron beam down to just a few nanometers and raster-scan it across their sample in small, precise steps. At each of the hundreds of thousands of probe positions in their experiment, they record an independent diffraction pattern, building up a massive dataset.
The achievement advances the use of electron microscopes in crystallography. Recently, crystallographers have turned to a technique called microcrystal electron diffraction (MicroED) to analyze nanoscale samples. Since high-energy electrons interact with matter more strongly than X-rays, they allow scientists to image nanocrystals even smaller than the wavelength of visible light. Using electrons, researchers can now solve atomic structures from specimens previously considered too small to be usable.
Yet even MicroED has its limitations, according to first author Ambarneil Saha, postdoctoral fellow at NCEM. MicroED bathes everything in its path with a broad electron beam, typically a few micrometers wide. Then, researchers insert an aperture inside the microscope to try and isolate the signal from the target crystal. If multiple crystals clump together within the area covered by the aperture, their diffraction patterns also blur together, producing difficult-to-interpret results.
The team's custom-built detector, the 4D Camera, helped them overcome such limitations. Operating at a lightning-fast 87,000 frames per second, the 4D Camera -- installed on the TEAM 0.5 microscope at NCEM -- produces a bitrate around 1500 times faster than the average internet download speed in the U.S. This torrent of data is then streamed to the Perlmutter supercomputer at Berkeley Lab's National Energy Research Scientific Computing Center (NERSC), where dedicated algorithms compress and process it in real time.
"Our approach brings together expertise in detector engineering, supercomputing, electron microscopy, and crystallography," said Ercius. "To handle the deluge of data produced by our camera, we used Perlmutter to compress terabytes of sparse frames. We then figured out how to adapt programs from X-ray crystallography to process electron microscopy data from a unique new detector."
Mining data from MOFs
To demonstrate their method, the team worked with the model compound UiO-66, a metal-organic framework (MOF) that forms porous octahedral crystals roughly 300 nanometers wide. While this material had previously been characterized using X-rays, getting clean diffraction data required painstakingly growing much larger crystals.
The key breakthrough came from what the team calls "virtual apertures"-- a computational technique that lets them choose which parts of their sample to analyze. They can isolate individual nanocrystals within a conglomerate of nanocrystals, or even pinpoint the specific subregions within a single nanocrystal that produce the best data. Unlike physical apertures whose size and shape are fixed, these virtual apertures can be carefully drawn and optimized into whatever custom shape the researchers need to target atomic regions within a sample.
"Nanoscale virtual apertures give us the power to selectively pick the best parts and discard the defective parts, pixel by pixel," explained Saha. "As a crystallographer, that's a dream come true. Not only can we salvage specimens intractable with standard physical apertures, but we can also solve atomic structures from tiny, handpicked subregions within those specimens."
MOFs have been the focus of intense research for next-generation energy, health, and environmental technologies, culminating in the 2025 Nobel Prize in Chemistry shared by Berkeley Lab affiliate Omar Yaghi for their development, work that relied in part on crystallographic studies carried out at Berkeley Lab's Advanced Light Source.
The granular precision of Ercius and Saha's technique could prove transformative across many fields, they said. For example, the technique could help characterize porous MOFs designed for drug delivery or gas capture, providing new insights into how these tiny crystals capture, hold, and release cargo molecules.
"Ultimately, we'd like to develop 4D-STEM into a technique capable of solving single-crystal structures at even smaller length scales," Saha added. "Now we can realistically start targeting populations of unit cells historically inaccessible to crystallography altogether, which is exciting."
The Molecular Foundry and NERSC are DOE Office of Science user facilities at Berkeley Lab.
This work was supported by the DOE Office of Science and Berkeley Lab's Laboratory Directed Research and Development (LDRD) program.
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Lawrence Berkeley National Laboratory (Berkeley Lab) is committed to groundbreaking research focused on discovery science and solutions for abundant and reliable energy supplies. The lab's expertise spans materials, chemistry, physics, biology, earth and environmental science, mathematics, and computing. Researchers from around the world rely on the lab's world-class scientific facilities for their own pioneering research. Founded in 1931 on the belief that the biggest problems are best addressed by teams, Berkeley Lab and its scientists have been recognized with 17 Nobel Prizes. Berkeley Lab is a multiprogram national laboratory managed by the University of California for the U.S. Department of Energy's Office of Science.
DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.
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Original text here: https://newscenter.lbl.gov/2026/03/03/new-electron-microscopy-technique-reveals-atomic-structures-from-nanocrystals-once-considered-unsolvable/
