title: Diffusion Monte Carlo calculations of zero-point structures of partially deuterated isotopologues of H7(+).
abstract: Diffusion Monte Carlo calculations for all the deuterated H7(+) isotopologues and isotopomers were performed to determine their zero-point energies, and thus the stability of them. Based on these calculations, we conclude that the deuterium atom prefers the unbonded position in the central H3(+), and then the bonded position in H3(+). When two deuterium atoms are in the outer H2 units, forming a D2 is more stable than one deuterium in each H2 unit. We also discovered that some unstable isotopomers can rearrange to a more stable isotopomer through two types of isomerization: one is that a new H3(+) core is formed with more deuterium atoms in it; the other is that the deuterium in the central H3(+) goes from the interior (the bonded position) to the exterior (the unbonded position) while the number of deuterium atoms in the H3(+) does not change. Three transition states related to the isomerization were identified, two of which have not been reported previously. The corresponding reaction paths were also determined.
authors.affiliation: Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University , Atlanta, Georgia 30322, United States.
authors.forename: Chen
authors.initials: C
authors.lastname: Qu
authors.forename: Joel M
authors.initials: JM
authors.lastname: Bowman