Update references for dcf code

Author: sunqm

pyscf/mcdcft/dcfnal.py

@@ -22,6 +22,11 @@
     Dayou Zhang, Matthew R. Hermes, Laura Gagliardi and Donald G. Truhlar
     J. Chem. Theory and Comput. 2021 17 (5), 2775-2782
     DOI: 10.1021/acs.jctc.0c01346
+[2] DC24: A new density coherence functional for multiconfiguration
+    density-coherence functional theory. 
+    Dayou Zhang, Yinan Shu and Donald G. Truhlar
+    J. Comput. Chem. 2024.
+    DOI: 10.1002/jcc.27522
 '''
 
 from pyscf.lib import logger