TY - JOUR

T1 - Potential-energy surfaces for charge exchange between singly charged ions and a LiF surface

AU - Wirtz, Ludger

AU - Burgdörfer, Joachim

AU - Dallos, Michal

AU - Müller, Thomas

AU - Lischka, Hans

PY - 2003

Y1 - 2003

N2 - We analyze the adiabatic potential-energy surfaces relevant for neutralization of singly charged ions in slow vertical incidence onto a lithium fluoride surface. The surface is represented by a cluster of varying size augmented by point charges of alternating sign in order to include the proper Madelung potential of the ionic crystal. Our calculation proceeds on the multiconfiguration self-consistent-field and multireference configuration-interaction levels. Size-consistency corrections based on the Davidson correction and multireference averaged quadratic coupled cluster methods are included as well. We emphasize the importance of a proper treatment of electron correlation signifying the polarization of the surrounding cluster environment in ab initio calculations of charge transfer at surfaces. From the topology of the surfaces, in particular the existence or absence of avoided crossings (or, more generally, conical intersections), qualitative predictions for the neutralization process can be made. The comparative analysis of potential curves for [Formula Presented] [Formula Presented] [Formula Presented] and [Formula Presented] projectiles provides an explanation for the recently observed threshold behavior for potential sputtering.

AB - We analyze the adiabatic potential-energy surfaces relevant for neutralization of singly charged ions in slow vertical incidence onto a lithium fluoride surface. The surface is represented by a cluster of varying size augmented by point charges of alternating sign in order to include the proper Madelung potential of the ionic crystal. Our calculation proceeds on the multiconfiguration self-consistent-field and multireference configuration-interaction levels. Size-consistency corrections based on the Davidson correction and multireference averaged quadratic coupled cluster methods are included as well. We emphasize the importance of a proper treatment of electron correlation signifying the polarization of the surrounding cluster environment in ab initio calculations of charge transfer at surfaces. From the topology of the surfaces, in particular the existence or absence of avoided crossings (or, more generally, conical intersections), qualitative predictions for the neutralization process can be made. The comparative analysis of potential curves for [Formula Presented] [Formula Presented] [Formula Presented] and [Formula Presented] projectiles provides an explanation for the recently observed threshold behavior for potential sputtering.

UR - http://www.scopus.com/inward/record.url?scp=85037189050&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.68.032902

DO - 10.1103/PhysRevA.68.032902

M3 - Article

AN - SCOPUS:85037189050

SN - 1050-2947

VL - 68

SP - 13

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

IS - 3

ER -