Anharmonic freq

Questions
#1

Hello,

I get this error when trying to run an anharmonic freq computation: = Starting finite difference calculation for ANHAR =
Finite diff step size: 9.99854e-02 a.u.

Q-Chem fatal error occurred in module NumDrv/AnlDrvLst.C, line 84:

unregonized FD Coordinate

Please submit a crash report at Q-Chem Crash Reporter

Here is my input file:

$molecule
-1 2
Cu 1.777073464 0.062893086 0.001998914
Cu -1.037518197 0.151676540 -0.008304471
O 3.154177805 -0.949323325 0.006198118
O 0.419718595 1.158914112 0.002574133
O -3.681699504 -0.119558065 0.025705414
O -2.573084741 -0.867847615 -0.011620022
$end

$rem
method TPSSH
basis def2-tzvpd
jobtype opt
mem_total 4000
scf_algorithm diis_gdm
scf_max_cycles 300
ecp def2-ecp
geom_opt_max_cycles 300
GEOM_OPT_TOL_DISPLACEMENT 1
GEOM_OPT_TOL_GRADIENT 1
GEOM_OPT_TOL_ENERGY 1
$end

@@@

$molecule
read
$end

$rem
mem_total 4000
jobtype freq
method tpssh
basis def2-tzvpd
ecp def2-ecp
scf_algorithm diis_gdm
scf_max_cycles 300
ANHAR TRUE
VCI 2
$end

#2

I also face the same problem. Does anyone know the tips for anharmonic freq calculation??

#3

This stems from a recent bug that was introduced in Q-Chem v. 6.0. I don’t have a workaround but the bug has been fixed for the Q-Chem 6.2 release.

1 Like
#4

I heard the bug was fixed, and we can download the fixed Q-Chem at the download site.
I will reinstall the Q-chem and try to calculate anhharmonic freq.

#5

Yes, this bug has been fixed. If you have the Q-Chem v6.1 license, you can simply download our latest installer carrying this bug fix and re-install Q-Chem, following the instructions on Installation Instructions | Q-Chem . Please let us know if there are additional related concerns. Thank you.

1 Like
#6

I just met the same problem. Downloaded the latest version. Thank you!