diff --git a/docs.it4i/software/orca.md b/docs.it4i/software/orca.md
index 3f62415459eceea55e4268d3bd2ca301748e0ce2..00a695f488102918c05406a749508291acae77c6 100644
--- a/docs.it4i/software/orca.md
+++ b/docs.it4i/software/orca.md
@@ -2,65 +2,132 @@
ORCA is a flexible, efficient and easy-to-use general purpose tool for quantum chemistry with specific emphasis on spectroscopic properties of open-shell molecules. It features a wide variety of standard quantum chemical methods ranging from semiempirical methods to DFT to single- and multireference correlated ab initio methods. It can also treat environmental and relativistic effects.
-## Making ORCA Available
+## ORCA Available on the Cluster
-The following module command makes the latest version of orca available to your session
+Many versions of ORCA is available on our clusters. You can list all versions by `ml av` command.
```console
-$ module load ORCA/3_0_3-linux_x86-64
+$ ml av orca
+-------------------------- /apps/modules/chem --------------------------
+ ORCA/4_0_0-linux_x86-64 ORCA/4_0_1-linux_x86-64 ORCA/4.0.1.2 (D)
+
+ Where:
+ D: Default Module
+```
+
+## Serial Computation With ORCA
+
+You can test serial computation with this simple input file. Create a file called orca_serial.inp and fill it with following ORCA commands.
+
+```bash
+ # Taken from the Orca manual
+ # https://orcaforum.cec.mpg.de/OrcaManual.pdf
+ ! HF SVP
+ * xyz 0 1
+ C 0 0 0
+ O 0 0 1.13
+ *
+```
+
+Next, create a PBS submission file (interactive job can be used too).
+
+```bash
+#!/bin/bash
+#PBS -S /bin/bash
+#PBS -N ORCA_SERIAL
+#PBS -l select=1
+#PBS -q qexp
+
+ml ORCA/4.0.1.2
+${EBROOTORCA}orca orca_serial.inp
```
-### Dependency
+Submit the job to the queue and wait before it ends. Then you can find an output log in your working directory.
```console
-$ module list
-Currently Loaded Modulefiles:
- 1) /opt/modules/modulefiles/oscar-modules/1.0.3(default)
- 2) GCC/4.9.3-binutils-2.25
- 3) binutils/2.25-GCC-4.9.3-binutils-2.25
- 4) GNU/4.9.3-2.25
- 5) icc/2015.3.187-GNU-4.9.3-2.25
- 6) ifort/2015.3.187-GNU-4.9.3-2.25
- 7) iccifort/2015.3.187-GNU-4.9.3-2.25
- 8) numactl/2.0.10-iccifort-2015.3.187-GNU-4.9.3-2.25
- 9) hwloc/1.11.1-iccifort-2015.3.187-GNU-4.9.3-2.25
- 10) OpenMPI/1.8.8-iccifort-2015.3.187-GNU-4.9.3-2.25
- 11) ORCA/3_0_3-linux_x86-64
+$ qsub submit_serial.pbs
+1417552.dm2
+
+$ ll ORCA_SERIAL.*
+-rw------- 1 hra0031 hra0031 0 Aug 21 12:24 ORCA_SERIAL.e1417552
+-rw------- 1 hra0031 hra0031 20715 Aug 21 12:25 ORCA_SERIAL.o1417552
+
+$ cat ORCA_SERIAL.o1417552
+
+ *****************
+ * O R C A *
+ *****************
+
+ --- An Ab Initio, DFT and Semiempirical electronic structure package ---
+
+ #######################################################
+ # -***- #
+ # Department of molecular theory and spectroscopy #
+ # Directorship: Frank Neese #
+ # Max Planck Institute for Chemical Energy Conversion #
+ # D-45470 Muelheim/Ruhr #
+ # Germany #
+ # #
+ # All rights reserved #
+ # -***- #
+ #######################################################
+
+
+ Program Version 4.0.1.2 - RELEASE -
+
+...
+
+ ****ORCA TERMINATED NORMALLY****
+TOTAL RUN TIME: 0 days 0 hours 0 minutes 1 seconds 47 msec
```
-## Example Single Core Job
+## Running ORCA in Parallel
-Create a file called orca_serial.inp that contains the following orca commands
+Your serial computation can be converted to parallel in a very simple way. You simply have to specify the number of parallel processes by directive **%pal**. In this example, 4 nodes, 16 cores each are used.
-```cpp
- # My first ORCA calculation :-)
- #
+!!! warning
+ Don't use **! PAL** directive as only PAL2 to PAL8 is recognized!
+
+```bash
# Taken from the Orca manual
# https://orcaforum.cec.mpg.de/OrcaManual.pdf
! HF SVP
+ %pal
+ nprocs 64 # 4 nodes, 16 cores each
+ end
* xyz 0 1
C 0 0 0
O 0 0 1.13
*
```
-Create a Sun Grid Engine submission file called submit_serial.sh that looks like this
+You also need to edit the previously used PBS submission file. You have to specify number of nodes, cores and MPI-processes to run.
-```console
-!/bin/bash
+```bash
+#!/bin/bash
+#PBS -S /bin/bash
+#PBS -N ORCA_PARALLEL
+#PBS -l select=4:ncpus=16:mpiprocs=16
+#PBS -q qexp
-module load ORCA/3_0_3-linux_x86-64
-orca orca_serial.inp
+ml ORCA/4.0.1.2
+${EBROOTORCA}/orca orca_parallel.inp
```
-Submit the job to the queue with the command
+!!! note
+ When running ORCA in parallel, ORCA should **NOT** be started with mpirun: e.g. mpirun -np 4 orca etc. like many MPI programs and has to be called with full pathname.
+
+Submit this job to the queue and see the output file.
```console
-$ qsub -q qexp -I -l select=1
-qsub: waiting for job 196821.isrv5 to start
-qsub: job 196821.isrv5 ready
-[username@r37u04n944 ~]$ ./submit_serial.sh
+$ qsub submit_parallel.pbs
+1417598.dm2
+$ ll ORCA_PARALLEL.*
+-rw------- 1 hra0031 hra0031 0 Aug 21 13:12 ORCA_PARALLEL.e1417598
+-rw------- 1 hra0031 hra0031 23561 Aug 21 13:13 ORCA_PARALLEL.o1417598
+
+$ cat ORCA_PARALLEL.o1417598
*****************
* O R C A *
@@ -80,19 +147,44 @@ qsub: job 196821.isrv5 ready
# -***- #
#######################################################
+
+ Program Version 4.0.1.2 - RELEASE -
...
- ****ORCA TERMINATED NORMALLY****
-TOTAL RUN TIME: 0 days 0 hours 0 minutes 2 seconds 796 msec
-[username@r37u04n944 orca]$ logout
+ ************************************************************
+ * Program running with 64 parallel MPI-processes *
+ * working on a common directory *
+ ************************************************************
-qsub: job 196821.isrv5 completed
+...
+ ****ORCA TERMINATED NORMALLY****
+TOTAL RUN TIME: 0 days 0 hours 0 minutes 11 seconds 859 msec
```
+You can see, that the program was running with 64 parallel MPI-processes. In version 4.0.1.2, only the following modules are parallelized:
+
+* ANOINT
+* CASSCF / NEVPT2
+* CIPSI
+* CIS/TDDFT
+* CPSCF
+* EPRNMR
+* GTOINT
+* MDCI (Canonical-, PNO-, DLPNO-Methods)
+* MP2 and RI-MP2 (including Gradient and Hessian)
+* MRCI
+* PC
+* ROCIS
+* SCF
+* SCFGRAD
+* SCFHESS
+* SOC
+* Numerical Gradients and Frequencies
+
## Register as a User
-You are encouraged to register as a user of Orca at [Here](https://orcaforum.cec.mpg.de/) in order to take advantage of updates, announcements and also of the users forum.
+You are encouraged to register as a user of ORCA at [Here](https://orcaforum.cec.mpg.de/) in order to take advantage of updates, announcements and also of the users forum.
## Documentation
-A comprehensive [.pdf](https://orcaforum.cec.mpg.de/OrcaManual.pdf) manual is available online.
+A comprehensive [PDF](https://orcaforum.cec.mpg.de/OrcaManual.pdf) manual is available online.