CCL:G: Basis set: where are 2px, 2py, 2pz



Dear all,

Thanks for your replies. It was very helpful and solved my problem.

Regards
Mehboob

On Thu, May 20, 2021, 17:55 Igors Mihailovs igorsm a http://cfi.lu.lv">cfi.lu.lv <owner-chemistry_._ccl.net> wrote:
Dear Mehboob,

It's because there is no point in writing down the same exponents once again. The definition of basis set usually includes just the exponents and contraction coefficients, which are the same for pc, py and pz (and analogously for d functions), which only have the angular part different.

Best regards,
Igors Mihailovs


On 20 May 2021 13:36:37 EEST, "Mehboob Alam mehboob.cu*gmail.com" <owner-chemistry===ccl.net> wrote:
Dear researchers,

This is about the basis set. We know that if we use 6-31G basis set for a H2O molecule then there would be 13 basis functions and 30 Gaussian Primitive Functions (GPFs). These numbers are also printed in the output file from a quantum chemical software (say g16). However, if I download the basis set for O- and H-atoms from EMSL I'm unable to identify the 30 GPFs. I could count only 22. It seems for 2p orbital (there is no GPFs separately for 2px, 2py, and 2pz) Am I missing something? It would be great if someone could explain it.

Here is the basis function from EMSL

H     0
 S    3   1.00
       0.1873113696D+02       0.3349460434D-01
       0.2825394365D+01       0.2347269535D+00
       0.6401216923D+00       0.8137573261D+00
 S    1   1.00
       0.1612777588D+00       1.0000000
 ****
 O     0
 S    6   1.00
       0.5484671660D+04       0.1831074430D-02
       0.8252349460D+03       0.1395017220D-01
       0.1880469580D+03       0.6844507810D-01
       0.5296450000D+02       0.2327143360D+00
       0.1689757040D+02       0.4701928980D+00
       0.5799635340D+01       0.3585208530D+00
 SP   3   1.00
       0.1553961625D+02      -0.1107775495D+00       0.7087426823D-01
       0.3599933586D+01      -0.1480262627D+00       0.3397528391D+00
       0.1013761750D+01       0.1130767015D+01       0.7271585773D+00
 SP   1   1.00
       0.2700058226D+00       0.1000000000D+01
 0.1000000000D+01

Best Regards,
Mehboob

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