Packet Size - Variable (one packet per data set)
| IDN | Description |
| 1 | data set number (1 for data set 1, etc.) |
| 11 | molecular formula as char string (72 chars) |
| 12 | calculated molecular or formula mass in Daltons |
| 13 | molecular or formula Z (see also lrsymm:) |
| 14 | measured molecular or formula mass in Daltons |
| 15 | e.s.d. in formula mass |
| 21 | calculated density (see also lrexpl:87) |
| 22 | F(000) |
| 23 | E(000) |