Table 2.
− FA | σ A | − FB | − FM | − FD | n | |||
---|---|---|---|---|---|---|---|---|
1,000,000 | 4.139 (1) | 0.0246 (5) | 4.08 (2) | 4.045 (4) | 4.11 (2) | 4.092 (2) | 4.10 (1) | 362 |
2,000,000 | 4.124 (1) | 0.0175 (6) | 4.06 (2) | 4.077 (4) | 4.09 (2) | 4.100 (2) | 4.09 (1) | 179 |
4,000,000 | 4.116 (1) | 0.0110 (9) | 4.10 (1) | 4.097 (3) | 4.11 (1) | 4.107 (2) | 4.108(7) | 125 |
10,000,000 | 4.1124 (6) | 0.0083 (5) | 4.10 (1) | 4.102 (1) | 4.10 (1) | 4.1070 (9) | 4.105 (6) | 170 |
20,000,000 | 4.1102 (6) | 0.0060 (5) | 4.10 (1) | 4.105 (1) | 4.11 (1) | 4.1074 (8) | 4.107 (4) | 99 |
TI | 4.108 (1) | 4.108 (1) | 4.108 (1) | 4.108 (1) | 4.108 (1) | 4.108 (1) |
Free energy values are given as Ac/εN where Ac is the configurational freeenergy (equation (40)), ε is the standard Lennard-Jones energy parameter (see text) and N is the number of atoms FA (equation (21)) is a lower bound of the free energy and σA (equation (23)) is its fluctuation. FB (equations (25) and (26)) is an upper bound and (equation (30)) is its corresponding Gaussian approximation. FM (equation (27)) and (equation (31)) are the averages of FA with FB and , respectively. FD (equation (33)) is the direct estimate for the free energy. is the average number of MC steps per cell, and n is the number of configurations analyzed (the sample size), where a single HSMC reconstruction was performed on each configuration. Results obtained by thermodynamic integration are denoted as TI. The statistical error appears in parenthesis; for example, 4.108(1) = 4.108±0.001.