GMX-NMR(1)

✨ GMX-NMR(1) ✨

okay bestie, welcome to the GROMACS manual page for gmx-nmr 💖 this one lives in section 1 of the manual and it's literally the whole vibe: analyzing your nuclear magnetic resonance properties straight out of an energy file. no cap.

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🌸 NAME 🌸

gmx-nmr — analyze nuclear magnetic resonance properties from an energy file 🧲✨

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💅 SYNOPSIS 💅

gmx nmr [-f [<.edr>]] [-f2 [<.edr>]] [-s [<.tpr>]] [-viol [<.xvg>]]
        [-pairs [<.xvg>]] [-ora [<.xvg>]] [-ort [<.xvg>]]
        [-oda [<.xvg>]] [-odr [<.xvg>]] [-odt [<.xvg>]]
        [-oten [<.xvg>]] [-b <time>] [-e <time>] [-[no]w]
        [-xvg <enum>] [-[no]dp] [-skip <int>] [-[no]aver]
        [-[no]orinst] [-[no]ovec]

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🦋 DESCRIPTION 🦋

so gmx nmr pulls distance restraint data or orientation restraint data out of an energy file. and bestie, it does not just quietly do it — it prompts you to interactively pick which terms you want. main character energy, honestly. 👑

when the -viol option is set, the time averaged violations get plotted, and the running time-averaged and instantaneous sum of violations get recalculated. also, you can plot running time-averaged and instantaneous distances between selected pairs with the -pairs option. two-for-one, we love to see it. 💖

the options -ora, -ort, -oda, -odr and -odt are the ones you reach for when you're analyzing orientation restraint data. the first two plot the orientation, the last three plot the deviations of the orientations from the experimental values. here's the cheat code iykyk 🔑:

• the options that end on an 'a' plot the average over time as a function of restraint.
• the options that end on a 't' prompt the user for restraint label numbers and plot the data as a function of time.
• -odr plots the RMS deviation as a function of restraint.

and when your run used time or ensemble averaged orientation restraints, you can use -orinst to analyze the instantaneous, not ensemble-averaged, orientations and deviations instead of the time and ensemble averages. switching it up ✨

-oten plots the eigenvalues of the molecular order tensor for each orientation restraint experiment. and with -ovec, the eigenvectors get plotted too. slay. 🌈

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👑 OPTIONS 👑

🍓 Options to specify input files

• -f [<.edr>] (ener.edr) — the energy file 📂
• -f2 [<.edr>] (ener.edr) (Optional) — another energy file 👯
• -s [<.tpr>] (topol.tpr) (Optional) — the portable xdr run input file

🎀 Options to specify output files

• -viol [<.xvg>] (violaver.xvg) (Optional) — an xvgr/xmgr file
• -pairs [<.xvg>] (pairs.xvg) (Optional) — an xvgr/xmgr file
• -ora [<.xvg>] (orienta.xvg) (Optional) — an xvgr/xmgr file
• -ort [<.xvg>] (orientt.xvg) (Optional) — an xvgr/xmgr file
• -oda [<.xvg>] (orideva.xvg) (Optional) — an xvgr/xmgr file
• -odr [<.xvg>] (oridevr.xvg) (Optional) — an xvgr/xmgr file
• -odt [<.xvg>] (oridevt.xvg) (Optional) — an xvgr/xmgr file
• -oten [<.xvg>] (oriten.xvg) (Optional) — an xvgr/xmgr file

💜 Other options

• -b <time> (0) — time of the first frame to read from the trajectory (default unit is ps) ⏰
• -e <time> (0) — time of the last frame to read from the trajectory (default unit is ps) ⏳
• -[no]w (no) — view the output .xvg, .xpm, .eps and .pdb files 👀
• -xvg <enum> (xmgrace) — xvg plot formatting, and your choices are: xmgrace, xmgr, none
• -[no]dp (no) — print energies in high precision 🔬
• -skip <int> (0) — skip this number of frames between data points 🦘
• -[no]aver (no) — also print the exact average and rmsd stored in the energy frames (only when 1 term is requested) 📊
• -[no]orinst (no) — analyse instantaneous orientation data ⚡
• -[no]ovec (no) — also plot the eigenvectors with -oten 🌈

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🔥 SEE ALSO 🔥

• gmx(1)

more info about GROMACS is available at <http://www.gromacs.org/>. go look, bestie, it's giving resources 🫶

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🌟 COPYRIGHT 🌟

2026, GROMACS development team

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and that's the whole page, no notes 💅 this was GROMACS 2026.4, dated Oct 02, 2026, and it's the GMX-NMR(1) page — iconic, periodt. 💖✨