Rex,

There are people more qualified to answer your question 1 than I am, so I am going to politely defer that answer. The answer depends on the unit cell dimensions, detector distance etc, and yes, there are more observations rejected due to overlap than would be the case in monochromatic data collection. As for 2, you should not freeze your crystals but mount them the old-fashioned way in capillaries. In practice neutron diffraction does not cause radiation damage to your crystals so you should not freeze and collect data as much as your time allotment allows for.

Hope this helps.

Mark van der Woerd

-----Original Message-----
From: REX PALMER <[log in to unmask]>
To: CCP4BB <[log in to unmask]>
Sent: Wed, Sep 21, 2011 3:52 am
Subject: [ccp4bb] Neutron data collection