Monte Carlo simulations, free-energy perturbation, and OPLS-AA energetics for organic molecules and their solutions. One download per computer, with everything BOSS needs to run. BOSS is available, academic and commercial, at no cost.
Or run a calculation here without installing anything.
For M1–M4 Macs. Every program in the download is a native Apple Silicon program, so nothing else is needed — not even Rosetta.
For 64-bit Intel/AMD systems. The programs are native 64-bit and self-contained; the only package needed is the C shell, for the BOSS scripts: sudo apt install tcsh.
For Windows 10 and 11. Unzip and go — nothing else to install. Native 64-bit programs.
Another computer? Intel Macs (2019 and earlier) and ARM Linux don't have a build yet. From any computer you can still run BOSS calculations and LigParGen on this website.
Manuals: BOSS 5.1 · BOSS 4.9, for older installations · MCPRO.
Nothing to install first — every program in it is native to Apple Silicon. BOSS cannot handle paths longer than 80 characters and does not say so — it reports a missing file instead. A folder directly in your home directory is safe; a deep path inside iCloud Drive is not.
cd ~
tar xzf MacBOSS51_64-1126.tar.gzThis catches almost everybody upgrading. The scripts run under csh, which re-reads ~/.cshrc, so an old setenv BOSSdir line there silently overrides whatever you set and you run your previous BOSS. The symptom is usually a confusing error about the wrong CPU type.
grep BOSSdir ~/.cshrcAdd this to your shell profile so it persists.
setenv BOSSdir ~/boss # csh/tcsh
export BOSSdir=~/boss # bash/zshThis optimises ethylene glycol and should print an energy in well under a second. If you see Optimized energy =, BOSS is working.
mkdir ~/bosstest && cd ~/bosstest
cp $BOSSdir/testjobs/consearch/etdiol.z .
csh $BOSSdir/scripts/xOPT etdiol
grep 'Optimized en' outBOSS and its tools are native 64-bit programs and need nothing else; the driver scripts are written in csh. (Only the old RasMol viewer included in the download is still 32-bit; it is optional.)
sudo apt install tcshBOSS silently truncates paths at 80 characters and then reports a missing file. Keep the install and your working directories short.
cd ~
tar xzf boss1126.tar.gzThe scripts run under csh, which re-reads ~/.cshrc. An old setenv BOSSdir line there silently overrides your environment and runs the wrong BOSS.
grep BOSSdir ~/.cshrcAdd this to your shell profile so it persists.
export BOSSdir=~/bossThis optimises ethylene glycol. If you see Optimized energy =, BOSS is working.
mkdir ~/bosstest && cd ~/bosstest
cp $BOSSdir/testjobs/consearch/etdiol.z .
csh $BOSSdir/scripts/xOPT etdiol
grep 'Optimized en' outExtract BOSS51w-1126.zip at the top of a drive so you end up with C:\boss. BOSS truncates paths past 80 characters and then reports a missing file, so avoid deep folders like Desktop\Downloads chains or OneDrive paths.
rem In File Explorer: right-click BOSS51w-1126.zip → Extract All → C:\
rem You should now have C:\boss with BOSS.exe insideThe .bat scripts find everything through the %BOSSdir% environment variable. setx stores it permanently — close and reopen the Command Prompt afterwards so it takes effect.
setx BOSSdir C:\bossThe bundled note is explicit: miscexec\cygwin1.dll is a library autozmat needs — do not delete it or move it out of that folder.
rem nothing to run — just don't tidy it awayIn a new Command Prompt, this optimises ethylene glycol via the xOPT batch script, the same first check we use on Mac and Linux. If out contains Optimized energy =, BOSS is working — these exact steps pass on our automated Windows test run.
mkdir %USERPROFILE%\bosstest && cd /d %USERPROFILE%\bosstest
copy %BOSSdir%\testjobs\consearch\etdiol.z .
set PATH=%BOSSdir%\scripts;%BOSSdir%\miscexec;%PATH%
call xOPT etdiol
findstr "Optimized" outOne thing no guide will tell you: BOSS's x* scripts do not check whether each step worked. A script can print a success message, exit cleanly and still leave you with an empty output file. Before trusting a run, check that the files you expected are actually there and not zero bytes.