basis-plus-lattice.typ

#import "@preview/cetz:0.3.1": canvas, draw
#import draw: content, circle, group, rect

#set page(width: auto, height: auto, margin: 8pt)

#let atom(pos, color) = {
  circle(pos, radius: 0.25, fill: color.lighten(20%), stroke: 0.3pt)
}

#canvas({
  // Constants for layout
  let spacing = 4
  let motif-x = 1
  let lattice-x = spacing
  let crystal-x = 2 * spacing

  // Draw motif/basis
  group({
    atom((motif-x, 0.8), blue)
    atom((motif-x + .5, 1.3), red)
  })
  content((motif-x, -1), text(size: 10pt)[Motif/Basis])

  // Plus sign
  content((motif-x + 0.45 * spacing, 1), text(size: 22pt)[+])

  // Draw point lattice
  group({
    for x in range(3) {
      for y in range(3) {
        circle(
          (x + lattice-x, y),
          radius: 0.1,
          fill: black,
          stroke: none,
        )
      }
    }
  })
  content((lattice-x + 1, -1), text(size: 10pt)[Point Lattice])

  // Equals sign
  content((lattice-x + 0.72 * spacing, 1), text(size: 22pt)[=])

  // Draw crystal structure
  group({
    // Draw unit cell outline
    rect((crystal-x, 0), (crystal-x + 1, 1), stroke: black + 1pt)

    // Draw atoms
    for x in range(3) {
      for y in range(3) {
        atom((x + crystal-x, y), blue)
        atom((x + crystal-x + 0.5, y + 0.5), red)
      }
    }
  })
  content((crystal-x + 1.5, -1), text(size: 10pt)[Crystal Structure])
})