Gaussian Bugs and Issues

Gaussian Bugs and Issues

Section to place any suspected bugs and errors

CASSCF

1. Quartic linear search updated in l103 seems to change which inital CASSCF guess is read (Lee).

   Use IOp(4/5=1) to read from the checkpoint file.

   Only a problem with GDV versions (GDVH13 and GDVH23 checked), not G09 (G09A02 and G09C01 checked)

2. Freq and StateAverage kewords are incompatible. Fix needs to use Freq and IOp for SA (David).
3. NBO analysis with CAS - attempting to save NBOs to checkpoint file causes core dump.

   Use IOp(3/32=5).

   Tested for gdv versions h01-h23 and g09 c01-d01.

4. Calculation of gradients with nocpmcscf does not work. Usually the gradient is computed via links l1101 and l1003, but without solving the CP-MCSCF equations the gradient should just be computed in overlay 7. However, the route that is build does not call links l701, l702 and l703, and therefore the gradient is not computed. Workaround is to build a non-standard route and call these links explicitly.

CIS

1. Geometry optimization gives a core dump when reading initial guess vectors from the rwf. (Lee)

   Use IOp(9/49=3) to force read from the checkpoint file.

   The checkpoint file must be available to read from in the first step.If this is not the case run a single point and then run the optimization using the SP chk file with the IOp

   Checked with GDVH13 only.

Opt

Modredundant

1. Using the Frozen coordinate command whilst setting the value for the coordinate (i.e. B 1 2 2.2 F which should freeze the bond distance between atoms 1 and 2 to 2.2 angstrom) sets the correct angle but does not freeze it. (Lee)

   Build the coordinate and freeze in different specifications e.g.

   B 1 2 2.2 B
   B 1 2 F
   

Freq

1. Same route generated by keyword or under NonStd may have a different behavior. Default behavior on a Freq calculation is to store force constants on the checkpoint file (no explicit option in overlay 99). However, when building a non-standard route, IOp(99/5=20) must be entered explicitly otherwise data is not stored to checkpoint. (Tested in g09 and gdv)