table of contents
g_nmeig(1) | GROMACS suite, VERSION 4.5.4-dev-20110404-bc5695c | g_nmeig(1) |
NAME¶
g_nmeig - diagonalizes the HessianSYNOPSIS¶
g_nmeig -f hessian.mtx -s topol.tpr -of eigenfreq.xvg -ol eigenval.xvg -qc quant_corr.xvg -v eigenvec.trr -[no]h -[no]version -nice int -xvg enum -[no]m -first int -last int -T real -[no]constrDESCRIPTION¶
g_nmeig calculates the eigenvectors/values of a (Hessian) matrix, which can be calculated with mdrun. The eigenvectors are written to a trajectory file ( -v). The structure is written first with t=0. The eigenvectors are written as frames with the eigenvector number as timestamp. The eigenvectors can be analyzed with g_anaeig. An ensemble of structures can be generated from the eigenvectors with g_nmens. When mass weighting is used, the generated eigenvectors will be scaled back to plain Cartesian coordinates before generating the output. In this case, they will no longer be exactly orthogonal in the standard Cartesian norm, but in the mass-weighted norm they would be.FILES¶
-f hessian.mtx InputHessian matrix
Run input file: tpr tpb tpa
xvgr/xmgr file
xvgr/xmgr file
xvgr/xmgr file
Full precision trajectory: trr trj cpt
OTHER OPTIONS¶
-[no]hnoPrint help info and quit
Print version info and quit
Set the nicelevel
xvg plot formatting: xmgrace, xmgr or none
Divide elements of Hessian by product of sqrt(mass) of involved atoms prior to diagonalization. This should be used for 'Normal Modes' analysis
First eigenvector to write away
Last eigenvector to write away
Temperature for computing quantum heat capacity and enthalpy when using normal mode calculations to correct classical simulations
If constraints were used in the simulation but not in the normal mode analysis (this is the recommended way of doing it) you will need to set this for computing the quantum corrections.
SEE ALSO¶
gromacs(7)Mon 4 Apr 2011 |