More descriptive names for single-letter variables

[janosh]

Just a stylistic PR but improves readability imo. Single-letter variable names are a pet peeve of mine. From personal experience, more descriptive variable names make code easier to maintain in the long run, esp. for people who didn't write the code originally.

[janosh]

Is this split() method used anywhere? How is it different from torch.split()?

https://github.com/CederGroupHub/chgnet/blob/ce85dee18764824ca492b7150ae37bcd81635312/chgnet/model/model.py#L608-L618

[codacy-production[bot]]

Coverage summary from Codacy

Merging #42 (ce85dee18764824ca492b7150ae37bcd81635312) into main (da7a8d1213251828b8a002eef808f2f237bdc053) - See PR on Codacy

Coverage variation	Diff coverage
Report missing for da7a8d1213251828b8a002eef808f2f237bdc053[^1]	33.33%

Coverage variation details

| | Coverable lines | Covered lines | Coverage | | ------------- | ------------- | ------------- | ------------- | | Common ancestor commit (da7a8d1213251828b8a002eef808f2f237bdc053) | Report Missing | Report Missing | Report Missing | | | Head commit (ce85dee18764824ca492b7150ae37bcd81635312) | 1172 | 882 | 75.26% | **Coverage variation** is the difference between the coverage for the head and common ancestor commits of the pull request branch: ` - `

Diff coverage details

| | Coverable lines | Covered lines | Diff coverage | | ------------- | ------------- | ------------- | ------------- | | Pull request (#42) | 12 | 4 | **33.33%** | **Diff coverage** is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: `/ * 100%`

See your quality gate settings    Change summary preferences

[^1]: Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct.