ising

FEP methods on Ising models

Compute free energy difference between ferromagnet (J>0) and anti-ferromagnet (J<0).

$$ E = -J\sum_{<i,j>}S_i S_j - H \sum_i S_i $$

plan

1. sample 1 ensemble
   1. ferromagnetic and anti-ferromagnetic
   2. another choice of J, say J=0 and H=0
2. sample 2 ensembles, then process with BAR
3. sample more than 2 ensembles

commands

• sample-ising:
• analyze-ensemble: get averages and standard deviations from an ensemble

TODO

• implement BAR