Computation of vibrational frequencies for adsorbates on surfaces

✍ Scribed by John D. Head

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 209 KB
• Volume: 65
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)65:5<827::aid-qua47>3.0.co;2-u

✦ Synopsis

A general strategy for computing the vibrational frequencies of adsorbates on surfaces is presented. Rather than use numerical fits to the surface energy, we advocate diagonalizing a mass weighted energy second-derivative matrix. The computation of energy derivatives has several advantages: It facilitates a more accurate treatment of the adsorbatersubstrate mass ratios. The normal modes of the surface vibrations are given automatically in the diagonalization step. Finally, a major advantage of using energy derivatives is that they provide estimates of the range of the adsorbatersubstrate interactions which can be used to ensure that the frequency values are converged. We illustrate the strategy for cluster calculations which simulate the Ž . Ž . Ž . Ž .