Overview

Updated binomial, and Poisson by @bjornstenqvist in #14
Updated manual, documentation, and created multipole_field by @bjornstenqvist in #15
Include ion-quadrupole interactions by @bjornstenqvist in #16
Updated neutralizing background and truncated Ewald by @bjornstenqvist in #17
Truncated Ewald, among others by @bjornstenqvist in #18
Reciprocal Ewald terms by @mlund in #19
Refactoring of Ewalddata and reciprocal Ewald by @mlund in #21
Split headers into separate files by @mlund in #22
Create cmake-single-platform.yml by @mlund in #23
[breaking] Add interface library target and modernize CMake build by @mlund in #24

Full Changelog: v1.2...v1.3

✨ Features

Quadrupole Support
- Added quadrupole potential and corresponding tests.
  e5c1a5a, a2b7c6d
- Implemented and tested fields for quadrupoles.
  12f3d89
- Added ion-quadrupole interactions: potential, fields, energies, and forces.
  34adf29
Multipole Improvements
- Added multipole_field functionality, extended documentation, and more tests.
  a3f4d7e
Ewald and Truncated Gaussian
- Added Ewald with truncated Gaussian and tests.
  a9c5b8d
- Added fields and forces for reciprocal, surface, and self terms.
  8f5a32b
- Added EwaldData struct and updated related functions.
  8c9f4e1
- Renamed EwaldT → EwaldTruncated.
  9d8c21f
- Placed truncated Ewald in a separate header file.
  3e4b2cf
New Interfaces and Build Modernization
- Added interface library target and modernized CMake build. (breaking change)
  af42c39
- Added CPM.cmake dependency handling and integration.
  f7c4b22, 6e3b19d
- Added GitHub Actions workflow for single-platform CI.
  f2e5c44

Added checks to raise errors for unsupported values of C.
2c4d8e7
Fixed override compiler warnings and added assertion to eval() for r2 != 0.
bc2e18d
Fixed JSON macro compatibility with newer JSON libraries.
2dfe89b
Fixed minor self-energy issue.
fc8b71c
Fixed cutoff handling in plain SO potential.
bb1e7e9

Major documentation updates including equations, explanations, and manual improvements.
5d9a2e1, 6c9b7f4, 9c2f8a7, b7a3e21
Added DOI references for various potentials (Fennell, ZeroDipole, RF, etc.).
ad9c3e2, 4bcf6a2
Updated README for out-of-source builds.
c8e5d23
Updated .zenodo.json metadata.
d5e1f42, f7b3c2e

Removed unnecessary functions and dependencies on external packages.
f4a91bc, 8d9e7a2
Added numKnots() function and tolerance control to spline Q-potential.
2c1a3e7
Exposed self_energy as a lean lambda function.
91f4e6a
Various code cleanups, renaming, and formatting updates.
d4f2c91, 8e7f3b1
Updated CPM.cmake to latest version.
8f9b3d2

Merge commits and minor updates not affecting functionality:
- b3e4f6a, d2c8b7e, e4c1f8d, a9d4c7b