When using this input file:
memory 5 gb
molecule ccl4 {
C
Cl 1 1.7817290513034312
Cl 1 1.7817290513034312 2 109.4710
Cl 1 1.7817290513034312 2 109.4710 3 120.0000
Cl 1 1.7817290513034312 2 109.4710 3 -120.0000
}
set {
basis cc-pV(D+d)Z
}
energy('ccsd')
The symmetry is detected as C3v, and the highest order abelian subgroup as Cs. Relevant part of the output:
==> Geometry <==
Molecular point group: cs
Full point group: C3v
Geometry (in Angstrom), charge = 0, multiplicity = 1:
Center X Y Z Mass
------------ ----------------- ----------------- ----------------- -----------------
C 0.000000000000 -0.000004468190 0.000000000000 12.000000000000
CL 0.000000000000 1.781724583113 0.000000000000 34.968852682000
CL -0.839916273116 -0.593907683266 1.454777659141 34.968852682000
CL -0.839916273116 -0.593907683266 -1.454777659141 34.968852682000
CL 1.679832546232 -0.593907683266 0.000000000000 34.968852682000
Running in cs symmetry.
The full point group should be Td, and the abelian subgroup used should be order 4. Is there any way to get Psi4 to use an order 4 symmetry group for this? Entering d2 group explicitly in the geometry section errors saying d2 is not a subgroup of c3v, entering c3 errors saying it’s an unknown group. I’ve tried reorienting the molecule so one of the axis in D2 is on the y axis; then the highest detected point group is C1, but the run is still in Cs.
I’m running a conda installation as per the instructions on the main site, the version of Psi4 is 1.1