Ab initio calculation of force constants and equilibrium geometries. III. Second-row hydrides
Abstract
Force constants of the molecules HF, NH3, CH4 and BH4- have been calculated ab initio by the force method with a 73/3 + 1 gaussian lobe basis set. The results, including a former calculation on H2O, agree well with experiment: the average relative error is 12 per cent for the diagonal force constants and the average absolute error is 0·06 mdyn/Å for the off-diagonal ones. The trends are also correctly reproduced. It is concluded that ab initio calculations of this accuracy can help to solve a number of spectroscopic problems. Force constants of BH4- have been determined from a combination of spectroscopic and ab initio information. Geometries have been obtained with little computing work and show good agreement with experiment.
- Publication:
-
Molecular Physics
- Pub Date:
- 1971
- DOI:
- 10.1080/00268977100101451
- Bibcode:
- 1971MolPh..21..329P