Generate Simulation Files
Inputs
| Input |
Required |
Default |
Description |
Nx, Ny |
No |
8 |
Lattice dimensions |
U |
No |
6.0 |
On-site interaction strength |
mu |
No |
0.0 |
Chemical potential |
tp |
No |
0.0 |
Next-nearest neighbor hopping |
dt |
No |
0.1 |
Imaginary time step |
L |
No |
40 |
Number of time slices (beta = L*dt) |
n_sweep_warm |
No |
200 |
Warmup sweeps |
n_sweep_meas |
No |
2000 |
Measurement sweeps |
Nfiles |
No |
1 |
Number of independent bins |
prefix |
No |
sim |
Output path prefix |
period_uneqlt |
No |
0 |
Unequal-time period (0=disabled) |
Outputs
{prefix}_0.h5, {prefix}_1.h5, ... - HDF5 simulation files{prefix}.h5.params - common params HDF5 file
Procedure
Option A: CLI (simple cases)
dqmc-util gen Nx=6 Ny=6 U=4.0 mu=0.0 dt=0.1 L=50 Nfiles=4 prefix=data/run/bin
Option B: Python (parameter scans)
from dqmc_util import gen_1band_hub
gen_1band_hub.create_batch(
prefix="data/run/bin", Nfiles=4,
Nx=6, Ny=6, U=4.0, mu=0.0, tp=0.0, dt=0.1, L=50
)
Choosing dt and L for a target temperature T:
import numpy as np
T = 0.25 # target temperature
U = 4.0
beta = 1.0 / T
dt = min((0.05/U)**0.5, beta / 10) # Trotter error constraint
L = int(np.ceil(beta / dt / 5) * 5) # L must be divisible by n_matmul and period_eqlt (defaults: 5)
dt = beta / L # recalculate exact dt
Validation
Failure Modes
| Symptom |
Cause |
Recovery |
| "File exists" error |
Previous files not cleaned |
Remove old files or use overwrite=1 argument |
| ValueError: L must be divisible ... |
L must be multiple of n_matmul and period_eqlt |
Adjust value of L and dt, keeping their product (beta) constant |
Do Not
- Overwrite existing simulation files without confirmation
- Ignore the Trotter error bound (
U * dt^2 <= 0.05)
