Update README.md

README.md

@@ -60,12 +60,12 @@ CVMFS_REPOSITORIES=sphenix.sdcc.bnl.gov
 
 
 ```
-singularity shell -B /cvmfs:/cvmfs /cvmfs/sphenix.opensciencegrid.org/singularity/rhic_sl7_ext.simg
+singularity shell -B /cvmfs:/cvmfs /cvmfs/sphenix.opensciencegrid.org/singularity/rhic_sl7_ext.sif
 source /opt/sphenix/core/bin/sphenix_setup.sh -n    # setup sPHENIX environment in the singularity container shell. Note the shell is bash by default
 root # give a test
 ```
 
-*For Singularity v3+, in particular CERN computing users: `rhic_sl7_ext.simg` might be slow to load under certain Singularity security settings at your computing center. In that case, please load with an alternative image: `singularity shell -B /cvmfs:/cvmfs /cvmfs/sphenix.opensciencegrid.org/singularity/rhic_sl7_ext`*
+*For Singularity v3+, in particular CERN computing users: `rhic_sl7_ext.sif` might be slow to load under certain Singularity security settings at your computing center. In that case, please load with an alternative image: `singularity shell -B /cvmfs:/cvmfs /cvmfs/sphenix.opensciencegrid.org/singularity/rhic_sl7_ext`*
 
 
 
@@ -95,7 +95,7 @@ This macro download the current release of sPHENIX/EIC-sPHENIX Singularity conta
 4. Start the container with 
 
 ```
-singularity shell -B cvmfs:/cvmfs cvmfs/sphenix.sdcc.bnl.gov/singularity/rhic_sl7_ext.simg
+singularity shell -B cvmfs:/cvmfs cvmfs/sphenix.sdcc.bnl.gov/singularity/rhic_sl7_ext.sif
 source /opt/sphenix/core/bin/sphenix_setup.sh -n   # setup sPHENIX environment in the singularity container shell. Note the shell is bash by default
 root # give a test
 ```
@@ -111,8 +111,8 @@ After entering the Singularity container, you can source sPHENIX environment and
 ```
 computer:~/> singularity shell <options depending on which of the two downloading options above>
 Singularity: Invoking an interactive shell within container...
-Singularity rhic_sl7_ext.simg:~/> source /opt/sphenix/core/bin/sphenix_setup.sh -n  
-Singularity rhic_sl7_ext.simg:~/> lsb_release  -a         # Verify same environment shows up as that on RCF
+Singularity rhic_sl7_ext.sif:~/> source /opt/sphenix/core/bin/sphenix_setup.sh -n  
+Singularity rhic_sl7_ext.sif:~/> lsb_release  -a         # Verify same environment shows up as that on RCF
 LSB Version:	:core-4.1-amd64:core-4.1-ia32:core-4.1-noarch
 Distributor ID:	Scientific
 Description:	Scientific Linux release 7.3 (Nitrogen)