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Peter Minary

Publications and source records attributed to Peter Minary.

3 recordsLinked to original sources

Ab initio molecular dynamics: concepts, recent developments, and future trends.

The methodology of ab initio molecular dynamics, wherein finite-temperature dynamical trajectories are generated by using forces computed "on the fly" from electronic structure calculations, has had a profound influence in modern theoretical research. Ab initio molecular dynamics allows chemical processes in condensed phases to be studied in an accurate and unbiased manner, leading to new paradigms in the elucidation of microscopic mechanisms, rationalization of experimental data, and testable predictions of new phenomena. The purpose of this work is to give a brief introduction to the technique and to review several important recent developments in the field. Several illustrative examples showing the power of the technique have been chosen. Perspectives on future directions in the field also will be given.

Biophysics↗

Reaction mechanism of cis-1,3-butadiene addition to the Si(100)-2 x 1 surface.

A set of 40 finite temperature ab initio molecular dynamics trajectories is employed to investigate the distribution of addition products and underlying microscopic mechanism of the addition of 1,3-butadiene to the Si(100)-2 x 1 surface. The product yields are in good agreement with recent STM measurements and include a Diels-Alder [4 + 2] adduct with a surface dimer acting as the dienophile, a [4 + 2]-like adduct that bridges two dimers within a row, a [4 + 2]-like adduct that bridges two dimers in adjacent rows, and an interdimer [2 + 2]-like adduct. The trajectories indicate that a common mechanism underlies the distribution and is predominantly a nonconcerted stepwise mechanism that proceeds via an intermediate zwitterion composed of a carbocation bonded to a negatively charged surface dimer.

Journal Article↗

Reaction pathway of the [4 + 2] Diels-Alder adduct formation on Si(100)-2 x 1.

Despite a long history of experimental and theoretical investigation, the mechanism of the Diels-Alder (DA) reaction has been controversial since its discovery 80 years ago. From these investigations, two schools of thought have emerged, namely that the reaction can proceed via a concerted, symmetric or asymmetric mechanism or via a nonconcerted mechanism involving a zwitterion or diradical as an intermediate. Here, we employ finite temperature ab initio molecular dynamics simulations, employing forces computed "on the fly" from electronic structure calculations, to investigate the microscopic mechanism of DA adduct formation between 1,3-butadiene and the Si(100)-2x1 surface. Free energy profiles and nonequilibrium trajectories strongly suggest a nonconcerted mechanism that forms a zwitterionic intermediate state. This mechanism, which begins with a nucleophilic attack of the C=C double bond on the positive member of a charge-asymmetric buckled Si-Si dimer, was previously shown to be common to the formation of a wide range of adducts that can form on the surface.

Journal Article↗