کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5429799 | 1397371 | 2010 | 22 صفحه PDF | دانلود رایگان |

A new, accurate, global, mass-independent, first-principles potential energy surface (PES) is presented for the ground electronic state of the water molecule. The PES is based on 2200 energy points computed at the all-electron aug-cc-pCV6Z IC-MRCI(8,2) level of electronic structure theory and includes the relativistic one-electron mass-velocity and Darwin corrections. For H216O, the PES has a dissociation energy of D0 = 41Â 109Â cmâ1 and supports 1150 vibrational energy levels up to 41Â 083Â cmâ1. The deviation between the computed and the experimentally measured energy levels is below 15Â cmâ1 for all the states with energies less than 39Â 000Â cmâ1. Characterization of approximate vibrational quantum numbers is performed using several techniques: energy decomposition, wave function plots, normal mode distribution, expectation values of the squares of internal coordinates, and perturbing the bending part of the PES. Vibrational normal mode labels, though often not physically meaningful, have been assigned to all the states below 26Â 500Â cmâ1 and to many more above it, including some highly excited stretching states all the way to dissociation. Issues to do with calculating vibrational band intensities for the higher-lying states are discussed.
Journal: Journal of Quantitative Spectroscopy and Radiative Transfer - Volume 111, Issue 9, June 2010, Pages 1043-1064