Molcas Forum

meilani.wibowo

Member

Registered: 2015-11-25

Posts: 9

Nuclear Charge

Hello,
I have a question regarding the nuclear charge. Is it possible to change the nuclear charge of an atom in Molcas? If it does so, how to do that? I've been looking for about it but it is not really clear for me how to do that. I've found in the manual in section 10.8 Extra information about basis sets and integrals how to write the basis set using pseudo code but I don't really understand about it. My idea is changing the nuclear charge of C atom into 6.50. Could somebody help me to explain about it? Thank you.

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: Nuclear Charge

I think it's enough to add "charge" in the basis definition, see the BASIs keyword in GATEWAY:

&GATEWAY
  Basis
    C.ANO-RCC-MB
    C1   0.00000000    -0.67683806     0.00000000 Angstrom
    Charge = 6.5
  End of basis
  Basis
    C.ANO-RCC-MB
    C2   0.00000000     0.67683806     0.00000000 Angstrom
  End of basis
  Basis
    H.ANO-RCC-MB
    H1   0.93807933    -1.24442493     0.00000000 Angstrom
    H2   0.93807933     1.24442493     0.00000000 Angstrom
    H3  -0.93807933    -1.24442493     0.00000000 Angstrom
    H4  -0.93807933     1.24442493     0.00000000 Angstrom
  End of basis

&SEWARD

&SCF

Note that the number of electrons will be computed from the total nuclear charge, if I'm not mistaken. That means that if both C have 6.5 charge each, the total nuclear charge will be 17, so you'd have to add "Charge = 1" in SCF if you still want 16 electrons.