oxiphysics_gpu/kernels/md_force/
virialstresstensorkernel_traits.rs1#[allow(unused_imports)]
12use super::functions::*;
13use crate::compute::ComputeKernel;
14
15use super::types::VirialStressTensorKernel;
16
17#[allow(clippy::needless_range_loop)]
18impl ComputeKernel for VirialStressTensorKernel {
19 fn name(&self) -> &str {
20 "VirialStressTensorKernel"
21 }
22 fn execute(&self, inputs: &[&[f64]], outputs: &mut [Vec<f64>], work_size: usize) {
23 if inputs.len() < 2 || outputs.is_empty() {
24 return;
25 }
26 let pos = inputs[0];
27 let epsilon = inputs[1][0];
28 let sigma = inputs[1][1];
29 let cutoff = inputs[1][2];
30 let n = work_size;
31 let cutoff2 = cutoff * cutoff;
32 let mut w = [0.0f64; 6];
33 for i in 0..n {
34 for j in (i + 1)..n {
35 let dx = pos[i * 3] - pos[j * 3];
36 let dy = pos[i * 3 + 1] - pos[j * 3 + 1];
37 let dz = pos[i * 3 + 2] - pos[j * 3 + 2];
38 let r2 = dx * dx + dy * dy + dz * dz;
39 if r2 >= cutoff2 || r2 < 1e-30 {
40 continue;
41 }
42 let r2_inv = 1.0 / r2;
43 let sr2 = sigma * sigma * r2_inv;
44 let sr6 = sr2 * sr2 * sr2;
45 let sr12 = sr6 * sr6;
46 let f_over_r2 = 24.0 * epsilon * (2.0 * sr12 - sr6) * r2_inv;
47 let r_vec = [dx, dy, dz];
48 let c = [(0usize, 0usize), (1, 1), (2, 2), (0, 1), (0, 2), (1, 2)];
49 for (ci, &(a, b)) in c.iter().enumerate() {
50 w[ci] -= r_vec[a] * f_over_r2 * r_vec[b];
51 }
52 }
53 }
54 outputs[0] = w.to_vec();
55 }
56}