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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.49A [2010] >
IJC-A Vol.49A(07) [July 2010] >
| Title: | DFT and statistical mechanics entropy calculations of diatomic and polyatomic molecules |
| Authors: | Serdaroglu, G
Durmaz, S |
| Keywords: | Theoretical chemistry
Ab initio calculations
Statistical mechanics
Entropy
Diatomic molecules
Polyatomic molecules |
| Issue Date: | Jul-2010 |
| Publisher: | CSIR |
| Abstract: | Ab initio/DFT and
statistical mechanics methods for calculation of entropy are reported for 20 molecules
in which internal rotations are absent, and are compared with the experimental
values. Agreement between these data and corresponding entropies calculated
from spectral data is excellent, being within one entropy unit in almost all
cases at 298.15 K. Entropies have also been calculated over a wide range of
temperature i.e., 298.15 K and 0–400 K at 50 K intervals. It is clearly
observed that all entropies increase with increasing temperature. The results
show a sharp increase on going from 0 K to 50 K while the increase is slight at
temperatures above 50 K. The results also suggest that such calculations may
assist in studies on entropies and equilibria involving species for which
vibrational frequencies can not easily be determined by experiment. |
| Page(s): | 861-866 |
| Source: | IJC-A Vol.49A(07) [July 2010]
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