Birnessite
Lanson B, Drits V A, Feng Q, Manceau A
American Mineralogist 87 (2002) 1662-1671
Structure of synthetic Na-rich birnessite: Evidence for a triclinic
one-layer unit cell
_database_code_amcsd 0002932
2.9513 2.9547 7.334 78.72 101.79 122.33 P-1
atom         x      y     z  occ Biso
Mn-layer     0      0     0   .5   .5
O-layer  .3886 -.3733 .1396       1.0
Na-Int    .628   .476  .481 .182  2.0
Wat-Int   .290  -.819  .496 .272  2.0