diff --git a/src/OPT/pair_ilp_tmd_opt.cpp b/src/OPT/pair_ilp_tmd_opt.cpp
index bfde0f78fd..5b70caae5c 100644
--- a/src/OPT/pair_ilp_tmd_opt.cpp
+++ b/src/OPT/pair_ilp_tmd_opt.cpp
@@ -23,7 +23,7 @@
      e-mail: qdgaoping at gmail dot com
 
    Optimizations are described in:
-     Gao, Ping and Duan, Xiaohui, et al: 
+     Gao, Ping and Duan, Xiaohui, et al:
        LMFF: Efficient and Scalable Layered Materials Force Field on Heterogeneous Many-Core Processors
      DOI: 10.1145/3458817.3476137
 
diff --git a/src/OPT/pair_saip_metal_opt.cpp b/src/OPT/pair_saip_metal_opt.cpp
index 2ac7cdc273..71275bf4df 100644
--- a/src/OPT/pair_saip_metal_opt.cpp
+++ b/src/OPT/pair_saip_metal_opt.cpp
@@ -23,7 +23,7 @@
      e-mail: qdgaoping at gmail dot com
 
    Optimizations are described in:
-     Gao, Ping and Duan, Xiaohui, et al: 
+     Gao, Ping and Duan, Xiaohui, et al:
        LMFF: Efficient and Scalable Layered Materials Force Field on Heterogeneous Many-Core Processors
      DOI: 10.1145/3458817.3476137