Displaying complex chords

Here is a way to display a chord where the same note is played twice with different accidentals.

\version "2.24.0"

fixA = {
  \once \override Stem.length = #11
}

fixB = {
  \once \override NoteHead.X-offset = #1.7
  \once \override Stem.length = #7
  \once \override Stem.rotation = #'(45 0 0)
  \once \override Stem.extra-offset = #'(-0.1 . -0.2)
  \once \override Flag.style = #'no-flag
  \once \override Accidental.extra-offset = #'(4 . -.1)
}


\relative c' {
  << { \fixA <b d!>8 } \\ { \voiceThree \fixB dis } >> s
}