bouwen zonder versie

git-svn-id: svn+ssh://gitlab/srv/svn-repos/pdb-redo/trunk@441 a1961a4f-ab94-4bcc-80e8-33b5a54de466

README.md

@@ -13,6 +13,8 @@ have been used.
 
 
 Other requirements are:
 Other requirements are:
 
 
+- A recent CCP4 environment (with the clipper libraries that have
+  electrion scattering support).
 - GNU make version 4.1 or higher.
 - GNU make version 4.1 or higher.
 - Boost libraries, the current version was developed using version 1.65
 - Boost libraries, the current version was developed using version 1.65
 - [mrc](https://github.com/mhekkel/mrc), a resource compiler that
 - [mrc](https://github.com/mhekkel/mrc), a resource compiler that