{
  "id": "1407.0477",
  "version": "v3",
  "published": "2014-07-02T08:20:05.000Z",
  "updated": "2014-08-07T11:56:33.000Z",
  "title": "A Variational Approach to Enhanced Sampling and Free Energy Calculations",
  "authors": [
    "Omar Valsson",
    "Michele Parrinello"
  ],
  "comment": "4 pages, 2 figures",
  "categories": [
    "cond-mat.stat-mech",
    "cond-mat.soft",
    "physics.chem-ph",
    "physics.comp-ph"
  ],
  "abstract": "The ability of widely used sampling methods, such as molecular dynamics or Monte Carlo, to explore complex free energy landscapes is severely hampered by the presence of kinetic bottlenecks. A large number of solutions have been proposed to alleviate this problem. Many are based on the introduction of a bias potential which is a function of a small number of collective variable. However constructing such a bias is not simple. Here we introduce a functional of the bias potential and an associated variational principle. The bias that minimizes the functional relates in a simple way to the free energy surface. This variational principle can be turned into a practical, efficient and flexible sampling method. A number of numerical examples are presented which include the determination of a three dimensional free energy surface. We argue that, beside being numerically advantageous, our variational approach provides a convenient standpoint for looking with novel eyes at the sampling problem.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2014-08-07T11:56:33.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "05.10.-a",
      "02.70.Ns",
      "05.70.Ln",
      "87.15.H-"
    ],
    "keywords": [
      "free energy calculations",
      "variational approach",
      "enhanced sampling",
      "bias potential",
      "variational principle"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1103/PhysRevLett.113.090601",
      "journal": "Physical Review Letters",
      "year": 2014,
      "month": "Aug",
      "volume": 113,
      "number": 9,
      "pages": "090601"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014PhRvL.113i0601V"
    }
  }
}