Dear All,

I need the help of a specialist in crystallography. I am solving a structure of a lanthanide based complex which is relatively large using XShell version 6.3.1 . In attempt to "Refine all non-H atoms anisotropically" I get the alert below.

Normal refinement works but I can't refine non-H atoms anisotropically. This implies that I can't also add H-atoms nor write the Crystallographic Information File (CIF).

The reason for the alert is given at the bottom part of the alert as ** ARRAYS TOO SMALL - INCREASE -b **. I am not sure I understand what this means. At first, I thought it was referring to the crystal unit cell dimension, but how possible is it for me to manually increase the b-axis? That doesn't make sense to me. Can anyone help? Thanks in advance.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

+ SHELXTL XLMP CRYSTAL STRUCTURE REFINEMENT - MULTI-CPU VERSION +

+ Copyright(c) Bruker AXS Inc. 1993-2014 Version 2014/7 +

+ 170921_DyAcOBTC2H5NVAA_py started at 10:37:23 on 20-Oct-2017 +

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Command line parameters: 170921_DyAcOBTC2H5NVAA_py_0m_a -a50000 -b3000 -c624 -t4

-a sets the approximate maximum number of atoms including hydrogens.

-b sets the maximum number of full-matrix parameters (leave unchanged for

CGLS). For example -b9000 allows refinement of 1000 anisotropic atoms or

3000 with BLOC 1. For a 32-bit version, -b times the square root of the

number of threads should not exceed about 65500. -c sets the reflection

buffer size. This depends on the CPU cache size but will rarely need

changing. -t sets the number of threads, otherwise the multi-CPU version

sets this equal to the number of available CPUs. For optimal performance

on systems with hyperthreading, usually the hyperthreading should be

switched off or -t used to halve the number of threads; e.g. -t4 rather

than -t8 for an Intel i7 processor.

Running 4 threads on 4 processors

Read instructions and data

Data: 12214 unique, 0 suppressed R(int) = 0.0912 R(sigma) = 0.1484

Systematic absence violations: 0 Bad equivalents: 0

3052 l.s. parameters for cycle 1

** ARRAYS TOO SMALL - INCREASE -b **

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

+ 170921_DyAcOB finished at 10:37:26 Total elapsed time: 3.71 secs +

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++