Diffusion Monte Carlo Calculations of Zero-Point Energies of Methanol and Deuterated Methanol |
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Authors: | Apurba Nandi Chen Qu Joel M Bowman |
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Institution: | Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 |
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Abstract: | Diffusion Monte Carlo (DMC) simulations have been used to obtain quantum zero-point energies of methanol and all its isotopologs and isotopomers, using a new, accurate semi-global potential energy surface. This potential energy surface is a precise, permutationally invariant fit to 6676 ab initio energies, obtained at the CCSD(T)-F12b/aug-cc-pVDZ level of theory. Quantum zero-point energies of deuterated methanol isotopomers are very close to each other and so a simple statistical argument can be used to estimate the populations of each isotopomer at very low-temperatures. The DMC simulations also indicate that there is virtually zero probability for H/D exchange in the zero-point state. © 2019 Wiley Periodicals, Inc. |
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Keywords: | diffusion Monte Carlo deuterated methanol zero-point energy potential energy surfaces |
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