From owner-chemistry@ccl.net Tue Nov 21 02:58:01 2017 From: "Andreas Klamt klamt!=!cosmologic.de" To: CCL Subject: CCL: Calculation of solution viscosity - qspr ? Message-Id: <-53072-171121012313-411-XA2paLI/m9kvG7tlGdeNdg**server.ccl.net> X-Original-From: Andreas Klamt Content-Language: de-DE Content-Type: multipart/alternative; boundary="------------16288427D03AAC11CF289D87" Date: Tue, 21 Nov 2017 07:23:02 +0100 MIME-Version: 1.0 Sent to CCL by: Andreas Klamt [klamt]~[cosmologic.de] This is a multi-part message in MIME format. --------------16288427D03AAC11CF289D87 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit We have a QSPR for ln_viscosity in our COSMOtherm software. It is heavily based on the finding, that the ln(viscosity) of a liquid is strongly influenced by size (surface area or volume are equally good) and the entropy of the liquid. Why entropy? Because high entropy means a lot of partner changes, because there are plenty of good partners for each piece of molecular surface in the soup.  Hence the barrier for a step of motion, which necessarily means partner changes, is low, and viscosity will be low. Low entropy means strong ordering and high viscosity. The entropy is calculated within our COSMO-RS thermodynamics. Best regards Andreas Am 20.11.2017 um 13:17 schrieb j j robinson jameschums]~[yahoo.com: > Hi Ahmed and CClers, > > Viscosity.. um..interesting.. would you perhaps be better off getting > some empirical data and build a QSPR model with PLS or similar or > would this be too inaccurate? > > J J Robinson - personal email - opinions are personal only. > > > On Monday, 20 November 2017, 11:12:16 CET, Josh Berryman > josh.berryman|,|uni.lu wrote: > > > > Sent to CCL by: "Josh  Berryman" [josh.berryman()uni.lu] > Ahmed, > > Finding viscosities is quite tricky as the correlation functions > involved have long tails, which need to be fully sampled.  I would > advise you to either get out a pen & paper to make an approximate > analytical solution, or else get yourself organised for a significant > undertaking.  This has been the nemesis of at least one graduate > student that I know. > > Allen & Tildesley's book is online (or the first ed is, anyway) to > give you an overview of the theory and practice for finding viscosity > via Green-Kubo method or via the Helfand moment. > > You will need to formulate a classical model, and to run your model I > can recommend EspressoMD as a (free) classical MD code which can carry > out the sampling while the code is running, to save the expensive step > of post-processing to find correlation functions.  The EspressoMD > documentation can give you some more practical tips here. > > EspressoMD also has the benefit of offering NEMD (with or without > Lees-Edwards boundary conditions), if you want to take the route of > imposing shear flow and measuring the response, rather than the more > basic technique of passively waiting for shear fluctuations and > measuring their correlation functions. > > Dr Josh Berryman > Uni Luxembourg> the strange characters on the top line to the .]![. sign. You can also> > E-mail to subscribers: CHEMISTRY.]![.ccl.net > or use: >      > > E-mail to administrators: CHEMISTRY-REQUEST.]![.ccl.net > or use >      <=> > >            > > -- Join us at the 5th-COSMO-RS-Symposium March 2018 Details at www.cosmologic.de/symposium_2018.html -------------------------------------------------- Prof. Dr. Andreas Klamt CEO / Geschäftsführer COSMOlogic GmbH & Co. KG Imbacher Weg 46 D-51379 Leverkusen, Germany phone +49-2171-731681 fax +49-2171-731689 e-mail klamt]![cosmologic.de web www.cosmologic.de [University address: Inst. of Physical and Theoretical Chemistry, University of Regensburg] HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt Komplementaer: COSMOlogic Verwaltungs GmbH HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt --------------16288427D03AAC11CF289D87 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit
We have a QSPR for ln_viscosity in our COSMOtherm software. It is heavily based on the finding, that the ln(viscosity) of a liquid is strongly influenced by size (surface area or volume are equally good) and the entropy of the liquid. Why entropy? Because high entropy means a lot of partner changes, because there are plenty of good partners for each piece of molecular surface in the soup.  Hence the barrier for a step of motion, which necessarily means partner changes, is low, and viscosity will be low. Low entropy means strong ordering and high viscosity.
The entropy is calculated within our COSMO-RS thermodynamics.

Best regards

Andreas

Am 20.11.2017 um 13:17 schrieb j j robinson jameschums]~[yahoo.com:
Hi Ahmed and CClers,

Viscosity.. um..interesting.. would you perhaps be better off getting some empirical data and build a QSPR model with PLS or similar or would this be too inaccurate?

J J Robinson - personal email - opinions are personal only.


On Monday, 20 November 2017, 11:12:16 CET, Josh Berryman josh.berryman|,|uni.lu <owner-chemistry.]![.ccl.net> wrote:



Sent to CCL by: "Josh  Berryman" [josh.berryman()uni.lu]
Ahmed,

Finding viscosities is quite tricky as the correlation functions involved have long tails, which need to be fully sampled.  I would advise you to either get out a pen & paper to make an approximate analytical solution, or else get yourself organised for a significant undertaking.  This has been the nemesis of at least one graduate student that I know.

Allen & Tildesley's book is online (or the first ed is, anyway) to give you an overview of the theory and practice for finding viscosity via Green-Kubo method or via the Helfand moment.

You will need to formulate a classical model, and to run your model I can recommend EspressoMD as a (free) classical MD code which can carry out the sampling while the code is running, to save the expensive step of post-processing to find correlation functions.  The EspressoMD documentation can give you some more practical tips here.

EspressoMD also has the benefit of offering NEMD (with or without Lees-Edwards boundary conditions), if you want to take the route of imposing shear flow and measuring the response, rather than the more basic technique of passively waiting for shear fluctuations and measuring their correlation functions.

Dr Josh Berryman
Uni Luxembourg



the strange characters on the top line to the .]![. sign. You can also

E-mail to subscribers: CHEMISTRY.]![.ccl.net or use:

E-mail to administrators: CHEMISTRY-REQUEST.]![.ccl.net or use


Before posting, check wait time at: http://www.ccl.net







-- 

Join us at the 5th-COSMO-RS-Symposium March 2018
Details at www.cosmologic.de/symposium_2018.html
--------------------------------------------------

Prof. Dr. Andreas Klamt
CEO / Geschäftsführer
COSMOlogic GmbH & Co. KG
Imbacher Weg 46
D-51379 Leverkusen, Germany

phone  	+49-2171-731681
fax    	+49-2171-731689
e-mail 	klamt]![cosmologic.de
web    	www.cosmologic.de

[University address:      Inst. of Physical and
Theoretical Chemistry, University of Regensburg]

HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
Komplementaer: COSMOlogic Verwaltungs GmbH
HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
--------------16288427D03AAC11CF289D87-- From owner-chemistry@ccl.net Tue Nov 21 13:46:01 2017 From: "Robert Molt r.molt.chemical.physics/a\gmail.com" To: CCL Subject: CCL: Calculation of solution viscosity - qspr ? Message-Id: <-53073-171121131147-29733-s4VanK6GbQQAs3dUB5tbsQ^server.ccl.net> X-Original-From: Robert Molt Content-Language: en-US Content-Type: multipart/alternative; boundary="------------469BF18373BADC9F1F8DBA77" Date: Tue, 21 Nov 2017 13:11:38 -0500 MIME-Version: 1.0 Sent to CCL by: Robert Molt [r.molt.chemical.physics,+,gmail.com] This is a multi-part message in MIME format. --------------469BF18373BADC9F1F8DBA77 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Andreas, are your findings published somewhere? On 11/21/17 1:23 AM, Andreas Klamt klamt!=!cosmologic.de wrote: > We have a QSPR for ln_viscosity in our COSMOtherm software. It is > heavily based on the finding, that the ln(viscosity) of a liquid is > strongly influenced by size (surface area or volume are equally good) > and the entropy of the liquid. Why entropy? Because high entropy means > a lot of partner changes, because there are plenty of good partners > for each piece of molecular surface in the soup.  Hence the barrier > for a step of motion, which necessarily means partner changes, is low, > and viscosity will be low. Low entropy means strong ordering and high > viscosity. > The entropy is calculated within our COSMO-RS thermodynamics. > > Best regards > > Andreas > > Am 20.11.2017 um 13:17 schrieb j j robinson jameschums]~[yahoo.com: >> Hi Ahmed and CClers, >> >> Viscosity.. um..interesting.. would you perhaps be better off getting >> some empirical data and build a QSPR model with PLS or similar or >> would this be too inaccurate? >> >> J J Robinson - personal email - opinions are personal only. >> >> >> On Monday, 20 November 2017, 11:12:16 CET, Josh Berryman >> josh.berryman|,|uni.lu wrote: >> >> >> >> Sent to CCL by: "Josh  Berryman" [josh.berryman()uni.lu] >> Ahmed, >> >> Finding viscosities is quite tricky as the correlation functions >> involved have long tails, which need to be fully sampled.  I would >> advise you to either get out a pen & paper to make an approximate >> analytical solution, or else get yourself organised for a significant >> undertaking.  This has been the nemesis of at least one graduate >> student that I know. >> >> Allen & Tildesley's book is online (or the first ed is, anyway) to >> give you an overview of the theory and practice for finding viscosity >> via Green-Kubo method or via the Helfand moment. >> >> You will need to formulate a classical model, and to run your model I >> can recommend EspressoMD as a (free) classical MD code which can >> carry out the sampling while the code is running, to save the >> expensive step of post-processing to find correlation functions.  The >> EspressoMD documentation can give you some more practical tips here. >> >> EspressoMD also has the benefit of offering NEMD (with or without >> Lees-Edwards boundary conditions), if you want to take the route of >> imposing shear flow and measuring the response, rather than the more >> basic technique of passively waiting for shear fluctuations and >> measuring their correlation functions. >> >> Dr Josh Berryman >> Uni Luxembourg >> >> >> >> the strange characters on the top line to the .|-|. sign. You can also >> >> E-mail to subscribers: CHEMISTRY.|-|.ccl.net >> or use:>> >> E-mail to administrators: CHEMISTRY-REQUEST.|-|.ccl.net >> or use<=> >> > > -- > > Join us at the 5th-COSMO-RS-Symposium March 2018 > Details atwww.cosmologic.de/symposium_2018.html > -------------------------------------------------- > > Prof. Dr. Andreas Klamt > CEO / Geschäftsführer > COSMOlogic GmbH & Co. KG > Imbacher Weg 46 > D-51379 Leverkusen, Germany > > phone +49-2171-731681 > fax +49-2171-731689 > e-mail klamt|-|cosmologic.de > web www.cosmologic.de > > [University address: Inst. of Physical and > Theoretical Chemistry, University of Regensburg] > > HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt > Komplementaer: COSMOlogic Verwaltungs GmbH > HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt > > -- Dr. Robert Molt Jr. r.molt.chemical.physics*_*gmail.com --------------469BF18373BADC9F1F8DBA77 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit

Andreas, are your findings published somewhere?


On 11/21/17 1:23 AM, Andreas Klamt klamt!=!cosmologic.de wrote:
We have a QSPR for ln_viscosity in our COSMOtherm software. It is heavily based on the finding, that the ln(viscosity) of a liquid is strongly influenced by size (surface area or volume are equally good) and the entropy of the liquid. Why entropy? Because high entropy means a lot of partner changes, because there are plenty of good partners for each piece of molecular surface in the soup.  Hence the barrier for a step of motion, which necessarily means partner changes, is low, and viscosity will be low. Low entropy means strong ordering and high viscosity.
The entropy is calculated within our COSMO-RS thermodynamics.

Best regards

Andreas

Am 20.11.2017 um 13:17 schrieb j j robinson jameschums]~[yahoo.com:
Hi Ahmed and CClers,

Viscosity.. um..interesting.. would you perhaps be better off getting some empirical data and build a QSPR model with PLS or similar or would this be too inaccurate?

J J Robinson - personal email - opinions are personal only.


On Monday, 20 November 2017, 11:12:16 CET, Josh Berryman josh.berryman|,|uni.lu <owner-chemistry.|-|.ccl.net> wrote:



Sent to CCL by: "Josh  Berryman" [josh.berryman()uni.lu]
Ahmed,

Finding viscosities is quite tricky as the correlation functions involved have long tails, which need to be fully sampled.  I would advise you to either get out a pen & paper to make an approximate analytical solution, or else get yourself organised for a significant undertaking.  This has been the nemesis of at least one graduate student that I know.

Allen & Tildesley's book is online (or the first ed is, anyway) to give you an overview of the theory and practice for finding viscosity via Green-Kubo method or via the Helfand moment.

You will need to formulate a classical model, and to run your model I can recommend EspressoMD as a (free) classical MD code which can carry out the sampling while the code is running, to save the expensive step of post-processing to find correlation functions.  The EspressoMD documentation can give you some more practical tips here.

EspressoMD also has the benefit of offering NEMD (with or without Lees-Edwards boundary conditions), if you want to take the route of imposing shear flow and measuring the response, rather than the more basic technique of passively waiting for shear fluctuations and measuring their correlation functions.

Dr Josh Berryman
Uni Luxembourg



the strange characters on the top line to the .|-|. sign. You can also

E-mail to subscribers: CHEMISTRY.|-|.ccl.net or use:

E-mail to administrators: CHEMISTRY-REQUEST.|-|.ccl.net or use


Before posting, check wait time at: http://www.ccl.net







-- 

Join us at the 5th-COSMO-RS-Symposium March 2018
Details at www.cosmologic.de/symposium_2018.html
--------------------------------------------------

Prof. Dr. Andreas Klamt
CEO / Geschäftsführer
COSMOlogic GmbH & Co. KG
Imbacher Weg 46
D-51379 Leverkusen, Germany

phone  	+49-2171-731681
fax    	+49-2171-731689
e-mail 	klamt|-|cosmologic.de
web    	www.cosmologic.de

[University address:      Inst. of Physical and
Theoretical Chemistry, University of Regensburg]

HRA 20653 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt
Komplementaer: COSMOlogic Verwaltungs GmbH
HRB 49501 Amtsgericht Koeln, GF: Prof. Dr. Andreas Klamt




-- 
Dr. Robert Molt Jr.
r.molt.chemical.physics*_*gmail.com
--------------469BF18373BADC9F1F8DBA77--