Rl. Murry et al., Molecular coordinates for instantaneous normal mode calculations. II. Application to CS2 and other triatomics, J CHEM PHYS, 110(21), 1999, pp. 10423-10432
We derive and demonstrate appropriate molecular coordinates for instantaneo
us normal mode calculations on liquids composed of linear and bent triatomi
c molecules. Comparisons are made between calculations in atomic Cartesian
and molecular coordinates, the latter using both laboratory-frame Euler-ang
le and molecular-frame rotational coordinates. Results are contrasted for c
oordinate systems with both rigid (with no internal degrees of freedom) and
flexible molecules. The coordinate dependences of the density of states, i
ts breakdown into translational and rotational contributions, participation
ratios and instantaneous normal mode (INM) spectroscopic quantities are ex
amined and discussed. (C) 1999 American Institute of Physics. [S0021-9606(9
9)50821-0].