Create a database user for ScientificCMS:
createuser -P scicms
PostgreSQL will ask you severeal question, including the password for the new database user.
Create a the database for ScientificCMS, owned by the user just created:
createdb -E UNICODE -O scicms scicms
Add support for the plpgsql language to the database:
createlang plpgsql scicms
The next steps depend if your using the RPM or the WAR package.