Achieving reliability of calculations for flat potential surfaces in density functional theory: The case of Al4 and Al4+1

✍ Scribed by Ana Martínez; Alberto Vela; Dennis R. Salahub

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 239 KB
• Volume: 63
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1997)63:2<301::aid-qua3>3.0.co;2-#

✦ Synopsis

Harmonic frequencies obtained by finite-differences from nonlocal density functional Ž . calculations are presented for the ground states of Al neutral and cationic . The effect of 4 varying the step size used in the finite-difference evaluation and the influence of the density convergence threshold are discussed. Potential energy curves along the most important normal coordinates are shown. With these results, we found that for Al the 4 square and the rhombus minima are almost degenerate with each other, while for Al q1 , 4 the rhombus is more stable and the square is a transition state.