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oxiphysics_gpu/kernels/md_force/
coulombkernel_traits.rs

1//! # CoulombKernel - Trait Implementations
2//!
3//! This module contains trait implementations for `CoulombKernel`.
4//!
5//! ## Implemented Traits
6//!
7//! - `ComputeKernel`
8//!
9//! 🤖 Generated with [SplitRS](https://github.com/cool-japan/splitrs)
10
11#[allow(unused_imports)]
12use super::functions::*;
13use crate::compute::ComputeKernel;
14
15use super::types::CoulombKernel;
16
17#[allow(clippy::needless_range_loop)]
18impl ComputeKernel for CoulombKernel {
19    fn name(&self) -> &str {
20        "CoulombKernel"
21    }
22    fn execute(&self, inputs: &[&[f64]], outputs: &mut [Vec<f64>], work_size: usize) {
23        if inputs.len() < 3 || outputs.len() < 2 {
24            return;
25        }
26        let pos = inputs[0];
27        let charges = inputs[1];
28        let k_e = inputs[2][0];
29        let cutoff = inputs[2][1];
30        let n = work_size;
31        let cutoff2 = cutoff * cutoff;
32        let mut forces = vec![0.0; n * 3];
33        let mut potential = 0.0;
34        for i in 0..n {
35            let xi = [pos[i * 3], pos[i * 3 + 1], pos[i * 3 + 2]];
36            let qi = charges[i];
37            for j in (i + 1)..n {
38                let xj = [pos[j * 3], pos[j * 3 + 1], pos[j * 3 + 2]];
39                let dx = xi[0] - xj[0];
40                let dy = xi[1] - xj[1];
41                let dz = xi[2] - xj[2];
42                let r2 = dx * dx + dy * dy + dz * dz;
43                if r2 >= cutoff2 || r2 < 1e-30 {
44                    continue;
45                }
46                let r = r2.sqrt();
47                let qj = charges[j];
48                potential += k_e * qi * qj / r;
49                let f_mag = k_e * qi * qj / (r2 * r);
50                forces[i * 3] += f_mag * dx;
51                forces[i * 3 + 1] += f_mag * dy;
52                forces[i * 3 + 2] += f_mag * dz;
53                forces[j * 3] -= f_mag * dx;
54                forces[j * 3 + 1] -= f_mag * dy;
55                forces[j * 3 + 2] -= f_mag * dz;
56            }
57        }
58        outputs[0] = forces;
59        outputs[1] = vec![potential];
60    }
61}