HNCACBSE pulse program notes.

SCH 7/2/02

The 1 td settings advised for planes in this version are wrong. 1 td should be as follows. 2 td (same as just td) should be 2K.

For N plane, set 1 td to 2*L4. ser file size will be 4 * (2*L4) * (2* td), typically 638976.
For C plane, set 1 td to 2*L6. ser file size will be 4* (2*L6) * (2* td), typically 1228800.
For 3D dataset, set 1 td to 4 * L4 * L6; correct?

The comments about indistinctness of the Nitrogen spectrum refer to 1D spectrums, not the processed 2D spectrum. I.e, it refers to the rser 1 spectrum, and to the appearance of the first dimension during nmrPipe processing. Typically forget looking for individual peaks in rser 1. Be happy if the maximum intensity in the left arm of the spectrum bulges up to about 3 x the noise, and there appears to be some clearance from the baseline. Don't expect to get an accurate phase determination until after the 2nd dimension is processed.

For 2D processing of planes, yMODE should be checked and changed to Complex in fid.com if it is not set that way by bruk2pipe. The Dim= comments just state which axis is ¹⁵N and which is ¹³C in 3D processing.

There is a typo in the pcpd3 pulse description. 6/20068Hz = 299u , not 5/20068Hz. Rephrasing this commentary:

First take the difference between the carbon carrier and the C=O resonance in ppm, typically (176 - 43 ppm =133 ppm.
Multiply by the zero-point reference frequency for carbon on this instrument (*150.89 = 20068 Hz. for the 600 MHz machine).
If using seduce1c6.jc divide 6 by the above frequency; if using seduce1c5.jc divide 5 by the above frequency. This yields the appropriate pulse time. In the above case 299u for seduce1c6.jc and 249u for seduce1c5.jc.
Optimize power to make that pulse time a 90 degree time. Nominally 10.83 dB for 299 usec or 9.35dB for 249u on the 600 MHz machine.
As far as I know, the choice between seduce1c6 and seduce1c5 is arbitrary.
As indicated, during calibration of the pulse, shift the carrier frequency (presumably at 43 ppm to start with) by -133 ppm (which is -20068 Hz on the 600 MHz machine).

Stopping the acquisition may leave the machine in a state that requires the following additional actions:

If the BSMS indicates "lock hold", use the command ii to reinitialize the interface.
If the BSMS continues to indicate pulses are occurring, type kill and terminate the orphaned processes.
If the BSMS lock light is flashing, it may be a good idea to toggle the lock key off, and then relock with lock d2o.