An algorithm for the uniform sampling of iso-energy surfaces and for the calculation of microcanonical averages

✍ Scribed by Arnaldo Rapallo

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 543 KB
• Volume: 27
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.20342

✦ Synopsis

Abstract

In this article an algorithm is proposed to efficiently perform the uniform sampling of an iso‐energy surface corresponding to a fixed potential energy U of a molecular system, and for calculating averages of certain quantities over microstates having this energy (microcanonical averages). The developed sampling technique is based upon the combination of a recently proposed method for performing constant potential energy molecular dynamics simulations [Rapallo, A. J Chem Phys 2004, 121, 4033] with well‐established thermostatting techniques used in the framework of standard molecular dynamics simulations, such as the Andersen thermostat, and the Nose–Hoover chain thermostat. The proposed strategy leads to very accurate and drift‐free potential energy conservation during the whole sampling process, and, very important, specially when dealing with high‐dimensional or complicated potential functions, it does not require the calculation of the potential energy function hessian. The technique proved to be very reliable for sampling both low‐ and high‐dimensional surfaces. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 414–425, 2006