.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "examples/dynamics/04_npt_integration.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. .. rst-class:: sphx-glr-example-title .. _sphx_glr_examples_dynamics_04_npt_integration.py: NPT Dynamics (MTK + Nosé-Hoover Chain) with Lennard-Jones Potential ================================================================== This example demonstrates isothermal-isobaric (NPT) dynamics using the Martyna-Tobias-Klein (MTK) barostat coupled with a Nosé-Hoover chain (NHC) thermostat, driven by the Lennard-Jones (LJ) potential. .. GENERATED FROM PYTHON SOURCE LINES 26-42 .. code-block:: Python from __future__ import annotations import matplotlib.pyplot as plt import numpy as np import warp as wp from _dynamics_utils import ( DEFAULT_CUTOFF, DEFAULT_SKIN, EPSILON_AR, SIGMA_AR, MDSystem, create_fcc_argon, pressure_atm_to_ev_per_a3, run_npt_mtk, ) .. GENERATED FROM PYTHON SOURCE LINES 43-71 .. code-block:: Python print("=" * 95) print("NPT (MTK + NHC) DYNAMICS WITH LENNARD-JONES POTENTIAL") print("=" * 95) print() device = "cuda:0" if wp.is_cuda_available() else "cpu" print(f"Using device: {device}") print("\n--- Creating FCC Argon System ---") positions, cell = create_fcc_argon(num_unit_cells=4, a=5.26) # 256 atoms print(f"Created {len(positions)} atoms in {cell[0, 0]:.2f} ų box") print("\n--- Initializing MD System ---") system = MDSystem( positions=positions, cell=cell, epsilon=EPSILON_AR, sigma=SIGMA_AR, cutoff=DEFAULT_CUTOFF, skin=DEFAULT_SKIN, switch_width=0.0, device=device, dtype=np.float64, ) print("\n--- Setting Initial Temperature ---") system.initialize_temperature(temperature=94.4, seed=42) .. rst-class:: sphx-glr-script-out .. code-block:: none =============================================================================================== NPT (MTK + NHC) DYNAMICS WITH LENNARD-JONES POTENTIAL =============================================================================================== Using device: cuda:0 --- Creating FCC Argon System --- Created 256 atoms in 21.04 ų box --- Initializing MD System --- Initialized MD system with 256 atoms Cell: 21.04 x 21.04 x 21.04 Å Cutoff: 8.50 Å (+ 0.50 Å skin) LJ: ε = 0.0104 eV, σ = 3.40 Å Device: cuda:0, dtype: Units: x [Å], t [fs], E [eV], m [eV·fs²/Ų] (from amu), v [Å/fs] --- Setting Initial Temperature --- Initialized velocities: target=94.4 K, actual=90.4 K .. GENERATED FROM PYTHON SOURCE LINES 72-86 .. code-block:: Python print("\n--- NPT Run (3000 steps) ---") print(f"Pressure units sanity: 1 atm = {pressure_atm_to_ev_per_a3(1.0):.6e} eV/ų") stats = run_npt_mtk( system=system, num_steps=3000, dt_fs=1.0, target_temperature_K=94.4, target_pressure_atm=1.0, tdamp_fs=500.0, pdamp_fs=5000.0, chain_length=3, log_interval=200, ) .. rst-class:: sphx-glr-script-out .. code-block:: none --- NPT Run (3000 steps) --- Pressure units sanity: 1 atm = 6.324209e-07 eV/ų Running 3000 NPT (MTK) steps at T=94.4 K, P=1.000 atm dt = 1.000 fs, tdamp = 500.0 fs, pdamp = 5000.0 fs, chain_length = 3 ======================================================================================================================== Step KE (eV) PE (eV) Total (eV) T (K) P (atm) V (Å^3) Neighbors min r (Å) max|F| ======================================================================================================================== 0 2.9787 -21.5621 -18.5833 90.37 483.900 9314.02 9984 3.713 2.313e-03 200 1.2863 -19.7064 -18.4201 39.02 1892.990 9315.31 10305 3.322 1.434e-01 400 1.6828 -19.9228 -18.2400 51.05 1730.950 9320.49 10255 3.299 1.882e-01 600 1.5355 -19.5738 -18.0382 46.59 1987.243 9329.58 10281 3.325 1.769e-01 800 1.9030 -19.7130 -17.8100 57.73 1854.898 9343.17 10253 3.221 2.158e-01 1000 2.0381 -19.5912 -17.5531 61.83 1927.512 9361.65 10266 3.264 1.809e-01 1200 2.1232 -19.3932 -17.2700 64.42 2017.448 9385.47 10255 3.271 2.251e-01 1400 2.2290 -19.2150 -16.9860 67.63 2080.926 9415.26 10238 3.161 3.116e-01 1600 2.4932 -19.2021 -16.7090 75.64 2009.581 9451.65 10206 3.236 2.207e-01 1800 2.6645 -19.0812 -16.4167 80.84 1990.881 9494.97 10190 3.175 2.831e-01 2000 2.8024 -18.9681 -16.1657 85.02 1964.547 9545.52 10196 3.245 1.976e-01 2200 2.8151 -18.7167 -15.9016 85.41 1992.528 9603.67 10170 3.205 2.329e-01 2400 2.8787 -18.5592 -15.6805 87.33 1935.112 9669.43 10087 3.221 2.472e-01 2600 3.0736 -18.5307 -15.4572 93.25 1766.366 9743.08 10041 3.223 2.592e-01 2800 2.9836 -18.2642 -15.2806 90.52 1753.716 9824.49 9969 3.233 2.417e-01 2999 3.1615 -18.2752 -15.1137 95.92 1519.791 9913.24 9970 3.189 2.508e-01 .. GENERATED FROM PYTHON SOURCE LINES 87-118 .. code-block:: Python print("\n--- Analysis ---") temps = np.array([s.temperature for s in stats]) pressures_atm = np.array([s.pressure for s in stats]) volumes = np.array([s.volume for s in stats]) steps = np.array([s.step for s in stats]) print(f" Mean Temperature: {temps.mean():.2f} ± {temps.std():.2f} K") print(" Target Temperature: 94.4 K") print() print(f" Mean Pressure: {pressures_atm.mean():.3f} ± {pressures_atm.std():.3f} atm") print(" Target Pressure: 1.0 atm") print() print(f" Mean Volume: {volumes.mean():.2f} ± {volumes.std():.2f} ų") fig, ax = plt.subplots(3, 1, figsize=(7.0, 6.5), sharex=True, constrained_layout=True) ax[0].plot(steps, temps, lw=1.5) ax[0].axhline(94.4, color="k", ls="--", lw=1.0, label="target") ax[0].set_ylabel("Temperature (K)") ax[0].legend(frameon=False, loc="best") ax[1].plot(steps, pressures_atm, lw=1.5) ax[1].axhline(1.0, color="k", ls="--", lw=1.0, label="target") ax[1].set_ylabel("Pressure (atm)") ax[1].legend(frameon=False, loc="best") ax[2].plot(steps, volumes, lw=1.5) ax[2].set_xlabel("Step") ax[2].set_ylabel(r"Volume ($\AA^3$)") fig.suptitle("NPT (MTK + NHC): Temperature, Pressure, and Volume") print("\n" + "=" * 95) print("SIMULATION COMPLETE") print("=" * 95) .. image-sg:: /examples/dynamics/images/sphx_glr_04_npt_integration_001.png :alt: NPT (MTK + NHC): Temperature, Pressure, and Volume :srcset: /examples/dynamics/images/sphx_glr_04_npt_integration_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none --- Analysis --- Mean Temperature: 73.29 ± 17.52 K Target Temperature: 94.4 K Mean Pressure: 1806.774 ± 368.263 atm Target Pressure: 1.0 atm Mean Volume: 9501.94 ± 189.24 ų =============================================================================================== SIMULATION COMPLETE =============================================================================================== .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 26.506 seconds) .. _sphx_glr_download_examples_dynamics_04_npt_integration.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: 04_npt_integration.ipynb <04_npt_integration.ipynb>` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: 04_npt_integration.py <04_npt_integration.py>` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: 04_npt_integration.zip <04_npt_integration.zip>` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_